WASHINGTON — A gridlocked Congress failed to do the big things: overhauling the nation’s immigrationsystem, reforming the loophole-cluttered tax code and stiffening background checks on gun buyers. Now it’s time to see whether it can just do the basics.

With just two weeks before lawmakers’ sacrosanct August break, progress is decidedly mixed on several must-pass items due to Capitol Hill partisanship, heightened by midterm elections and the Obama administration’s conflicting signals to Congress. Lawmakers must find about $10 billion to keep highway projects on track through next spring, ease long wait times for veterans seeking health care and deal with a humanitarian crisis of some 57,000 unaccompanied immigrant children who have entered the U.S. along the Southern border since last fall.

Looming large is legislation to keep the government operating beyond the start of the fiscal year on Oct. 1; the House has completed seven of the 12 spending bills while the Senate has done none. A once-promising effort to revive the appropriations process in the Senate appears to have derailed in a test of wills between top Senate leaders over the rights of Republicans to offer amendments to legislation.

“You have to be optimistic and you have to keep on working,” House Minority Leader Nancy Pelosi said Tuesday. “It’s just a stunning thing that no matter what it is, the president is for it, the Republicans are against it .”

The California Democrat said congressional critics are not “overstating” the severity of gridlock on Capitol Hill.

It’s looking increasingly possible, even likely, that the warring parties won’t come together to pass President Barack Obama’s request for $3.7 billion to help deal with children flooding into the country from Central America. The main roadblock is whether to also change a 2008 law that guarantees these minors, many of whom are fleeing violence, a hearing before an immigration judge.

“I doubt it,” said Sen. John McCain, R-Ariz., who helped craft a comprehensive Senate immigration bill last year that remains stalled in the House.

Congressional aides in both parties say the politics over changing the 2008 law to make it easier for the Border Patrol to immediately send back unaccompanied minors to Guatemala, El Salvador and Honduras has all but sunk Obama’s request. The administration has sent contradictory signals on whether it would be open to toughening the law — a non-negotiable demand of Republicans. Congressional Democrats are balking at using the emergency funding bill to advance changes to the 2008 statute.

Senate Majority Leader Harry Reid, D-Nev., accused Republicans on Monday of “resorting to ransoming children to get their way.”