An early December government shutdown is a real possibility, since a divided Congress can't agree on military spending, Democrats insist on help for young immigrants and President Donald Trump's position can change with each lawmaker he talks to.
Most of Washington is focused on overhauling the nation's tax code, but lawmakers face a combustible mix of must-do and could-do items, with the current government spending bill set to expire December 8.
On the list are immigration and a U.S.-Mexico border wall; an impasse over children's health care; pent-up demand for budget increases for the Pentagon and domestic agencies; and tens of billions of dollars in hurricane aid.
There's plenty at stake for Republicans controlling Washington. Politically, there's an urgency to avoid a debilitating shutdown just as the GOP hopes to wrap up an overhaul of the tax code that is its top priority.
And legions of GOP defense hawks are adamant that the Pentagon receive a huge 2018 budget hike approaching $80-90 billion. Trump and many followers want the U.S.-Mexico wall.
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Democrats retain considerable power in the endgame - their votes are needed - and are pressing demands of their own.
They want protections for immigrants who were brought to the U.S. illegally as young children. They also demand budget increases for domestic agencies.
'I think we're headed in a good direction on the spending caps,' Sen. Roy Blunt, R-Mo., said Monday. 'I don't know that will get to immigration this year but that's a pretty easy thing to settle if the Democrats will give the president some of what he wants.
'I think he would be willing to be pretty forward-leaning on kids who were brought to the country illegally.'
For his part, Trump tends to waver depending on the situation - siding with Democrats on a debt deal in September, and promising Republicans last week that the controversial immigration issue won't be part of the year-end spending measure.
Meanwhile, the tax debate is taking up energy, time and political capital, and GOP leaders seem reluctant to issue controversial decisions that might harm its chances.
A rundown of non-tax issues facing Congress and Trump includes:
Ideally, top leaders in both parties would like to agree on new spending levels and pass a catchall bill by the Dec. 8 deadline.
That's looking increasingly unlikely. Another temporary funding bill would be needed to avert a government shutdown, but many Democrats say they won't be able to support any measure that doesn't include help for so-called 'Dreamer' immigrants facing