WASHINGTON (AP) — There was a closed-door huddle by an embattled President Joe Biden with his own party's senators, apparently for naught. An eyebrow-raising speech on the Senate floor by a recalcitrant Democrat. And a defiant news conference by the top House Republican.

Each event occurred Thursday. None was helpful for Democrats. And all were snapshots from a day that underscored the divisiveness and futility washing over a largely gridlocked Washington during this jaggedly partisan time.

"I hope we get this done. The honest to God answer is I don't know whether we can get this done," Biden admitted to reporters after a lunchtime meeting with Senate Democrats, where he sought support for the party's latest foundering priority: voting rights legislation.

Biden said that even if the voting measure failed — as seemed certain — he'd stay in the fight "as long as I have a breath in me." Even so, the day's events illustrated his limited political capital at a time when his polling numbers are in the dumps and Democrats have almost no margin for error in a Congress they control by a hair's breadth.

Biden's party is focusing much of its energy these days on the voting rights bill and an investigation of the Jan. 6, 2021, attack on the Capitol by supporters of then-President Donald Trump trying to prevent lawmakers from certifying his reelection defeat. Both efforts are running headlong into GOP opposition.

In the case of the voting legislation — aimed at blunting GOP-passed state laws limiting access to voting, often by minorities — Democrats have pushed it through the narrowly divided House. But things are different in the 50-50 Senate, where they need unanimity before Vice President Kamala Harris can cast her tie-breaking vote.

Republicans have been blocking the voting legislation by filibusters, procedural landmines that take 60 votes to overcome. So Biden and Senate Majority Leader Chuck Schumer, D-N.Y., want Democrats to change the chamber's filibuster rules so it would take just a simple majority to pass voting rights legislation.

They could do that if all 50 Democratic senators were united behind the plan. But they're not.

Sens. Joe Manchin, D-W.Va., and Kyrsten Sinema, D-Ariz., have repeatedly said that while they back the voting rights push, they oppose weakening the filibuster rule without GOP support for fear of further fraying the brittle relationship between the two parties. They're the same two senators who've been the chief stumbling blocks to Biden's stalled 10-year, roughly $2 trillion social and environment bill, another top Democratic goal.

Though Sinema's opposition was well known, she took to the Senate floor Thursday to underline it — even as Biden was heading to Capitol Hill to meet with her and other Democrats. She said she wouldn't support changes "that worsen the underlying disease of division infecting our country."

Sinema's timing may have been designed to preemptively ease pressure on her during the session with Biden. But it was still a very public, startling show of resistance, one that may have been unthinkable under a president who — unlike Biden, who has a penchant for accommodation — had a reputation for retribution for such overt rebellion.

Manchin released a written statement after the Biden meeting, saying he would not vote to weaken the filibuster. Doing that would "only pour fuel onto the fire of political whiplash and dysfunction that is tearing this nation apart," he said.

Schumer said Biden "made a powerful and strong and impassioned presentation for us to get this done and we are going to do everything we can to pass these two bills."

Other Democrats said they think the risks of easing filibusters — which for decades have helped minority parties protect their priorities but have grown in use dramatically this century — are outweighed by the dangers state GOP voting restrictions pose.

"They're doing what they think is right," Sen. Jon Tester, D-Mont., said of Sinema and Manchin. "I happen to disagree."

As grating as their stances were with Democrats, they were praised by Republicans, who as minority party would benefit by keeping filibusters intact.

"It was extraordinarily important and she has, as a conspicuous act of political courage, saved the Senate as an institution," Senate Minority Leader Mitch McConnell, R-Ky., said of Sinema.

Also Thursday, House Minority Leader Kevin McCarthy, R-Calif., talked to reporters for the first time since releasing a statement the previous evening saying he would not cooperate with a special House committee investigating the Jan. 6 insurrection.

McCarthy said there is "nothing that I can provide the Jan. 6 committee" that would help their investigation and accused Democrats of using the probe for "pure politics."

McCarthy spoke with Trump by phone during the attack, and later that day said on the House floor that Trump "bears responsibility" for the assault.

But he visited Trump at his Florida estate days later and has since refrained from criticizing the former president. The special committee, which Democrats dominate 7-2, wants to know about his dealings with Trump.

The refusal to cooperate by McCarthy, who hopes to become speaker next year should Republicans win House control, is no surprise.

To win that post, he'd have to be elected to it by House Republicans — a pathway he could complicate by helping a probe of Trump, who holds sway over many in the GOP. Two other GOP lawmakers and Trump allies have also rejected the panel's requests for information, and many Republicans have said they consider the committee and its work to be illegitimate and partisan.

The committee's investigation will continue no matter what.

Still, McCarthy's defiance was the latest sign of how torn apart the parties are, unable to do what many Congresses in the past have done after major crises: mount a fully bipartisan investigation into them.