The game is the same, but many of the players have changed. Congress and the president are facing off in another supreme spending showdown. If they don't agree on a funding bill by the end of September 30, much of government will shutdown. This last happened in 2011, when Congress avoided a shutdown by passing a spending measure shortly after the midnight deadline hit. Who controls what happens this time? Take a look at the key players who will determine how this fight ends:
-- From CNN Capitol Hill Reporter Lisa Desjardins. CNN's Deirdre Walsh and Ted Barrett contributed to this report.
Rep. Mark Meadows, R-North Carolina -- The architect. During Congress' August recess, the tea party-backed freshman wrote to Republican leaders suggesting that they tie dismantling Obamacare to the funding bill. Though initially rejected by GOP leadership, 79 of Meadows' House colleagues signed on to the letter, which quoted James Madison writing in the Federalist Papers, "the power over the purse may, in fact, be regarded as the most complete and effectual weapon ... for obtaining a redress of every grievance."
Speaker John Boehner, R-Ohio -- The coach. He'll make the key play call. The top Republican leader in the land may be the most important player in the days immediately before a possible shutdown. Boehner could decide whether to push through the Senate's version of a spending bill and keep government running, or he could float a third version with some other Republican wish list items in it. If he takes the second option, Boehner could risk a shutdown but could also force the Senate into a tough position: give House Republicans something or send federal workers home. Timing on all this will be critical.
Sen. Ted Cruz, R-Texas -- The revolutionary or rabble rouser, depending on your viewpoint. The tea party firebrand could lead a long filibuster on the Senate floor, delaying passage of a spending bill until just one day before the deadline on Monday, September 30. Cruz has stoked the anti-Obamacare flames all summer, but recently angered fellow Republicans by openly saying that the Senate does not have the votes to repeal the health care law.
Sen. Marco Rubio, R-Florida -- Senator to watch. The potential presidential candidate has been one of three senators (Cruz and Mike Lee, R-Utah, being the others) pushing to use the government shutdown debate as a way to repeal or defund Obamacare. But watch his actions and language as a shutdown nears to see if he digs in or if downshifts at all.
Sen. Harry Reid, D-Nevada -- The man steering the ship in the Senate. Master at using Senate procedure to his advantage, Reid is the main force in controlling the voting process in the chamber and ensuring that an attempted filibuster by tea party-types fails. The majority leader will be a primary negotiator if we reach phase three, if the House does not accept the Senate spending bill.
Sen. Mitch McConnell, R-Kentucky -- If Reid steers the ship, McConnell controls the headwinds. Which is good news for Reid, at least initially. The Republican leader and several of his members say they will vote against Cruz's filibuster and in favor of a spending bill with no limits on Obamacare. Meaning, in favor of a bill that just funds government. McConnell generally has been leery of running into a shutdown or default. In fact, one legislative method for avoiding default is named after him.
Sen. Patty Murray, D-Washington -- The consigliore. Murray, center, does not seek the outside limelight, but the Senate Budget Committee chairwoman is a major fiscal force behind the scenes on Capitol Hill. Known by fellow Democrats as a straight shooter, she is also an experienced negotiator, having co-chaired the laborious, somewhat torturous and unsuccessful Super Committee.
Rep. Tom Graves, R-Georgia -- The new militia leader. The freshman congressman from Georgia, second from right, is one reason the debate has reached this point. Graves led the charge that blocked the original proposal by House Republican leaders. That would have kept government funded and had a detachable portion on Obamacare. Instead Graves and other conservatives forced their leaders to pass a spending bill with a mandatory defunding of Obamacare.
Rep. Peter King, R-New York -- The blunt statesman. King is outspoken against many tea party tactics, calling the move to tie Obamacare to the must-pass spending bill essentially a suicide mission and Cruz "a fraud." He is pushing for Republicans to accept a more "clean" spending bill that can pass the Senate and avoid a shutdown.
Thomas Donohue, president and CEO of the U.S. Chamber of Commerce -- The heavy. Donohue is known for his deep connections and his aggressive lobbying on behalf of business. He and the Chamber are urging Republican lawmakers to avoid a shutdown. The Chamber is an important political backer for conservatives, but has had mixed success with the current Congress, locking in firm anti-tax positions but unable to push through immigration reform so far.
Michael Needham, president of Heritage Action -- The driving force. Needham runs the political offshoot of the conservative Heritage Foundation and has been unrelenting in urging lawmakers to repeal Obamacare. He has told Republicans not to fear a potential shutdown, saying they would suffer more politically from allowing Obamacare to continue.
President Barack Obama -- The campaigner and CEO. Expect the president to use his podium more as a shutdown nears, aiming at public opinion as Democrats in Congress position themselves. If House Republicans send back a new proposal close to the September 30 deadline, the president and Democrats will have to decide what move to make next.
Rep. Eric Cantor, R-Virginia -- The powerful lieutenant. Cantor, the House Republican No. 2, is much more closely allied with conservatives and tea party members in the House than is Speaker Boehner. The two have not always agreed on every strategy during potential shutdown debates, but have been in public lockstep during the current go-around.
Rep. Nancy Pelosi, D-California, and Steny Hoyer, D-Maryland -- Players on deck. The top two House Democrats are mostly watching and waiting. But they will play a critical role once Boehner decides his next move. They could either bring Democratic votes on board a deal or be the loudest voices against a new Republican alternative. Hoyer will be interesting to watch; he has strongly opposed both the House and Senate plans as cutting too much in spending.
Rep. Kevin McCarthy, R-California -- The numbers guy. McCarthy, the House whip, has the tricky job of assessing exactly where Republican members stand and getting the 217 votes it takes to pass a bill in the chamber. He is known for his outreach to and connection with many of the freshmen House members who align with the tea party.
Rep. Paul Ryan, R-Wisconsin -- Member to watch. The vote of the House budget chairman and former vice presidential nominee is an important signal both within Republican ranks and to the public at large. Ryan has voted against some funding measures in the past, including the emergency aid for Superstorm Sandy recovery. But he was a "yes" on the last extension of the debt ceiling.
Rep. Ileana Ros-Lehtinen, R-Florida -- Another member to watch. A former committee chairwoman (Republican rules have term limits for committee chairs), Ros-Lehtinen knows House politics and procedure inside out. Depending on the issue, she has been described as a conservative or moderate, and occasionally as a libertarian.
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
Key players in the shutdown debate
STORY HIGHLIGHTS
- The new fiscal year has begun, but Congress couldn't agree on a spending deal in time
- House Republicans want a bill that include anti-Obamacare amendments
- Senate Democrats want a spending bill with no amendments attached
- More than 800,000 workers are expected to be furloughed starting Tuesday
(CNN) -- So what happens now that a shutdown is in place?
Republicans and Democrats couldn't agree on a spending plan for the fiscal year that started Tuesday as they wrangled over Obamacare, leaving federal coffers short.
Political effect of a government shutdown
Media coverage of Obamacare, shutdown
Obamacare: 'Duct tape and chicken wire'
GOP Rep: Senate is 'playing games'

A Park Service police officer stands guard in front of the Lincoln Memorial during a partial shutdown of the federal government in November 1995. Many government services and agencies were closed at the end of 1995 and beginning of 1996 as President Bill Clinton battled a Republican-led Congress over spending levels.
An employee hangs a sign on the door of the Smithsonian's National Air and Space Museum in Washington on November 14, 1995, marking the start of the government shutdown.
A tourist peers out a ferry window at the Statue of Liberty on November 14, 1995, as a small group of visitors wait on the dock to board the vessel. No passengers were allowed off the boat as both the Statue of Liberty and Ellis Island were closed after federal workers were sent home.
Sen. Pete Domenici, R-New Mexico, chairman of the Senate Budget Committee holds up a chart showing the differences between Republican and Democratic budgets as Speaker of the House Newt Gingrich, left, and Senate Majority Leader Bob Dole stand by during a press conference on Capitol Hill.
A police officer walks through the empty Statuary Hall in the Capitol on November 15, 1995.
The national debt clock in New York is stopped during the government shutdown in November.
President Clinton speaks about the federal budget impasse from the Oval Office on November 16, 1995. The first part of the budget shutdown ended on November 19 when a temporary spending bill was enacted. But Congress failed to come to an agreement on the federal budget, leading to a second shutdown starting December 16.
UPS workers deliver letters to members of Congress on November 28, 1995. The letters were written and sent by members of the Coalition For Change, a nonpartisan organization devoted to balancing the budget.
A speaks to demonstrators at the Capitol Rotunda on December 7, 1995. Evangelical leaders from around the country held a prayer session to call on legislators to treat the poor justly during welfare reform and budget negotiations.
House Appropriations Committee Chairman Rep. Bob Livingston, right, holds a "closed" sign outside the National Gallery of Art in Washington on December 18, 1995.
A security guard informs people that the passport office is closed at the Federal Building in Los Angeles on December 18, 1995.
Rep. John Boehner dumps out coal, which he called a Christmas gift to President Clinton, during a news conference about the federal budget on December 21, 1995.
Karen Bishop chains herself to colleagues during a rally at the Federal Building in San Francisco on January 3, 1996. The workers claimed they were in servitude to the government as hundreds of thousands of federal employees were either furloughed or had to work without pay.
Food service employees at the Veterans Hospital in Miami line up to receive food rations on January 3, 1996. Many federal employees faced financial hardships during the shutdown.
Tourists line up outside the National Gallery of Art in Washington on January 5, 1996. It was one of the few government buildings open during the shutdown thanks to the assistance of private funds.
People trying to apply for visas at the U.S. consulate in Paris on January 5, 1996, are told that the building is closed because of the U.S. budget crisis.
Rep. Thomas Davis III, R-Virginia, attends a rally in Washington on January 5, 1996, urging the end of the government shutdown.
Tourists view Yosemite National Park in California after it re-opened on January 6, 1996. Early that morning, President Clinton signed Republican-crafted legislation to restore jobs and provide retroactive pay to government workers while he and Congress continued negotiating how to balance the federal budget.
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
The last government shutdown
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Photos: The last government shutdown
Here's a quick Q&A to get you caught up on what happened and what to expect:
1. Why did the government shut down?
Congress has one key duty in the Constitution -- pass spending bills that fund the government. If it doesn't, most functions of government -- from funding agencies to paying out small business loans and processing passport requests -- grinds to a halt. But some services, like Social Security, air traffic control and active military pay, will continue to be funded. Oh, and Congress still gets paid, too.
2. Why does it have to pass a spending bill in the middle of the year?
It may be the middle of the calendar year, but the government's fiscal year runs from October 1 to September 30.
3. What was the holdup?
House Republicans insist any new spending bill include provisions to either defund, derail or otherwise chip away at Obamacare. Senate Democrats are just as insistent that it doesn't.
4. How is Obamacare tied to the spending bill?
The health care law isn't directly tied to funding the government, but it's being used as a bargaining chip. A group of Republicans, led by freshman Sen. Ted Cruz of Texas, believe the president's signature domestic policy achievement is so bad for the country that it is worth disrupting government funding to undercut it.
5. What are some of the objections to Obamacare?
The Patient Protection and Affordable Care Act, the actual name of the law, requires all Americans to have health insurance. Opponents say it'll hurt employers and amounts to overreach by the federal government. Some have also criticized the medical device tax that's part of the law, saying that by imposing such a tax, it's basically sending jobs overseas.
6. What's the Democrats' defense?
They say the law will expand access to health care and help rein in the rising costs of coverage. Obamacare prevents those with pre-existing medical conditions from being denied health insurance, and proponents say those who have health insurance will no longer have to indirectly pay for those who show up in emergency rooms uninsured.
Fact check: The myths and realities of Obamacare
7. What happened with the spending bill over the weekend?
The Republican-dominated House passed two spending bill amendments Sunday morning -- one that would delay Obamacare for a year and one that would repeal the Obamacare's medical device tax. The bill went back to the Senate, where Democrats who control that chamber have consistently said any changes to Obamacare would be a deal-killer.
8. What happened Monday?
The Senate rejected the latest House proposal, prompting the House to approve another spending plan that would remove the Obamacare individual mandate. The Senate rejected that, too, setting the stage for a shutdown.
9. What happened overnight?
House members voted to reaffirm the anti-Obamacare amendments that Senate Democrats have said would be a deal-breaker. They also requested a conference with the Senate to work out their differences.
10. What will happen Tuesday?
The Senate will reconvene and will likely make a decision on the House's offer to talk. But Senate Majority Leader Harry Reid said late Monday night that he wouldn't agree to such a meeting until the House presents a clean spending bill stripped of the amendments.
"We will not go to conference with a gun to our head," he said.
11. Has this happened before?
Yes, this shutdown is the first since late 1995. That one lasted 21 days, into 1996.
12. How many government workers could be furloughed?
Most of the 3.3 million government workers are deemed "essential" -- they'll keep working. But more than 800,000 government employees will sit at home, according to a CNN analysis.
Many of the furloughed federal workers are supposed to be out of their offices within four hours of the start of business Tuesday.
13. What will this do to the economy?
Depends on how long it lasts. If it's just a few days, the hit might not be severe. But the total economic impact is likely to be at least 10 times greater than the simple calculation of lost wages of federal workers, said Brian Kessler, economist with Moody's Analytics. His firm estimates that a three- to four-week shutdown would cost the economy about $55 billion.
14. How will this affect me?
In ways big and small. The mail will continue to come. The military will continue to fight. And Social Security checks will continue to be paid.
But if you need a federal loan to buy a house, you'll have to wait. If you want a gun permit or a passport, that won't happen anytime soon.
15. Will a shutdown kill Obamacare?
No. Most of the money for Obamacare comes from new taxes and fees, as well as from cost cuts to other programs like Medicare and other types of funding that will continue despite the government shutdown.
16. Will the president get paid during a shutdown?
Yes. His salary -- $400,000 -- is considered mandatory spending. It won't be affected.
17. What about House and Senate members?
They'll keep drawing checks, too. The 27th Amendment prevents any Congress from changing its own pay.
18. What does John Q. Public think of all this?
A CNN/ORC International poll that came out Monday found that 46% will blame congressional Republicans if the government closes its doors, with 36% saying the president would be more responsible and 13% pointing fingers at both.
19. Isn't there another matter -- the debt ceiling?
Ah yes, that's the next battle brewing. Remember that time when you maxed out your credit card? That's what the debt limit is all about. The U.S. is on the verge of maxing out its $16.699 trillion credit card. And the president must ask Congress to raise the country's credit limit.
But the debt ceiling debacle won't come to a head until October 17. Perhaps it's best to deal with one showdown at a time.
20. Can Congress agree on anything?
The House and Senate did agree on one thing. They finalized legislation Monday to keep paying troops in the event of a shutdown.
CNN's Leigh Ann Caldwell, Z. Byron Wolf, Adam Aigner-Treworgy, Laura Koran, Lisa Desjardins, Bryan Monroe, Chris Isidore and Gregory Wallace contributed to this report.