WASHINGTON — Add a potential government shutdown to President Donald Trump’s growing roster of headaches.

Beneath the capital’s radar looms a vexing problem — a catchall spending package that’s likely to top $1 trillion and could get embroiled in the politics of building Trump’s wall at the U.S.-Mexico border and a budget-busting Pentagon request.

While a shutdown deadline has a few weeks to go, the huge measure looms as an unpleasant reality check for Trump and Republicans controlling Congress.

Despite the big power shift in Washington, the path to success — and averting a shuttering of the government — goes directly through Senate Democrats, whose votes are required to pass the measure. And any measure that satisfies Democrats and their new leader, Sen. Chuck Schumer of New York, is sure to alienate tea party Republicans. Trump’s determination to build his wall on the U.S.-Mexico border faces a fight with Democrats, too.

For now, the new Democratic leader is cautious.

“We’ll have to wait and see what happens,” Schumer said. “I hope they won’t jam up the supplemental (spending bill) with poison pills.”

At issue is the annual must-do legislation funding government agencies and departments. The path for the huge spending measure — by Republicans’ own choice a piece of leftover business from last year — would be difficult and complicated in a smoothly running Washington. But partisanship has engulfed the city, and the upcoming measure is made even more challenging once upcoming Trump requests for $18 billion or more for the Pentagon and money for his contentious border wall are added to the mix.

For years, Republicans needed President Barack Obama’s signoff and relied on Democratic votes to pass the measures and balance out opposition from tea partyers.

Trump’s election has shifted the balance of power in Washington, but the GOP’s grip on the Senate — where 60 votes are needed for most legislation — is actually weaker. Some House conservatives are demanding a round of budget cuts to “offset” new spending on the Pentagon and Trump’s wall.

“If all of a sudden we’re not worried about pay-fors for our spending, then we have been hypocrites,” said tea party Rep. Raul Labrador, R-Idaho. “I’m not going to vote for anything that just increases spending without looking for a way to pay for that in the future.”