WASHINGTON – To achieve a government shutdown, wait until the very last minute to put forward a spending bill to keep the government open. Give the conservative flank of the GOP in the House -- which dislikes the bill -- time to pressure the rest of the party to oppose it. Instead of changing the bill to get Democrats to vote with Republicans, tweak it to appease conservatives, costing it any Democratic support. Pass the bill on Republican votes and watch it die in the Senate as time runs out.

That's the script that led up to the 16-day shutdown in October 2013. Last time the driving force was conservative anger over the implementation of the Affordable Care Act. This time, the right is incensed by President Barack Obama’s move to shelter 5 million undocumented immigrants through executive orders.

Republicans seem to be following the shutdown script again, but there are some signs that the party may be trying to strike a deal with Democrats. “I expect that we’ll have bipartisan support to pass the omnibus appropriation bill,” House Speaker John Boehner said. But until the legislation is filed next week, the risk remains that the fight over immigration could undo efforts to keep the government open.

Republican leadership is trying to move legislation that will fund the government through September 2015, except for the agencies that deal with immigration. Those functions would be funded only through early next year, allowing Republicans to reignite the fight over immigration in the spring.

In an effort to appease the conservatives who would rather go to battle right now, the House voted on a symbolic bill Thursday that would block the immigration executive orders. But that has done little to ease their anger.

Conservatives want the leadership to put forward a short-term continuing resolution that would fund the government only until early next year. They oppose the omnibus because it funds any part of government all the way until September. 

Boehner is talking confidently about his approach.

“I think we’ve laid out a reasonable course of action suggested by our members,” he said. “We did a lot of listening. This didn’t just happen overnight. I didn’t just wake up and have this idea in my head. We worked with an awful lot of our members, and frankly, I’m pretty comfortable with where we are.”

But Congress is on a tight deadline. The House GOP is waiting until the last minute to vote on a spending bill. The deadline to pass a bill is by Dec. 11. Members, both Republican and Democrat, are unlikely to see the bill until Tuesday, and most aren’t expecting a vote until Wednesday or Thursday, meaning there will be no time for fixes or changes.

Boehner said the decision to wait until the last minute couldn't be helped, that the legislators needed every minute to work out elements that must be agreed upon by the House and Senate. “They’re doing good work, but they’re not finished yet, it’s as simple as that,” Boehner said.

But this coming weekend allows time for problems to develop. Conservative activists (who some analysts think have lost clout) are still able to marshal thousands of loyalists to call Congress and voice their unhappiness. These groups -- like Club for Growth and For America -- used the same tactic in the run-up to the last shutdown.

For example, since Wednesday morning the anti-immigration Numbers USA has been working to activate its membership. Before it had even begun a full-out effort, the organization had already amassed 23,000 contacts through its social media pages and email list. 

Members will often say that these groups have no bearing on how they vote. But hundreds of messages left at a congressional office in opposition to a proposal can make lawmakers think twice.

If conservatives bail, the funding bill could still pass the House with Democratic support, but Boehner will have to ask for it.

House Minority Leader Nancy Pelosi said Thursday that she has reached out to Boehner to offer to help pass the bill. But that was the same thing she said repeatedly before the last shutdown. The speaker declined to accept her help.

Democrats have four elements that must be in the bill before they will support it, a senior Democratic aide said. There are about 75 riders that have yet to be negotiated that must be included, addressing such issues as National Security Agency reform, energy programs, drought relief for the West and marijuana laws in D.C. The bill must meet national security goals. It must avoid another shutdown in the spring. And it can’t undermine the president.

“I have extended the hand of friendship, once again, to the speaker to say: We stand ready to cooperate,” Pelosi said on Thursday. “If he has 218 votes, then there’s no conversation. If he doesn’t, we have leverage over those riders. I have confidence in [New York Rep.] Nita Lowey, our negotiator, and the Senate Democrats on the subject of the riders. But until we see the bill, there’s no way you can say you support it or not.”

But while Pelosi's help might be necessary to the bill's survival, it could create a problem for Boehner. He has to stand for re-election as speaker in January, and while he's almost certain to win, being seen to work with Pelosi won't make it easier from him to hang onto support from the right. 

Getting a deal with Pelosi “would be a very bad thing to do before we have our new Republican majority in the Senate,” Conservative Rep. Tim Huelskamp of Kansas said.