"The budget deal doesn't have everything Democrats want, it doesn't have everything the Republicans want, but it has a great deal of what the American people want", Schumer said on the Senate floor, later adding, "And now we must finish the job".
"I have no intention of yielding back", Pelosi said at 3:41 p.m.
Just over eight hours later, she concluded her record-breaking remarks.
The hope is that Pelosi and Democrats - whose support is often needed to pass spending bills in the face of opposition from fiscal conservatives - can pressure House Speaker Paul Ryan, R-Wis., to hold votes on immigration legislation, as the Senate is poised to begin doing next week. "Let the House work its will".
"Without that commitment from Speaker Ryan ... this package does not have my support, nor does it have the support of a large number of members of our caucus", Pelosi said. She said that former President Barack Obama's Deferred Action for Childhood.
But they have resisted President Trump's call for more border security and tighter immigration laws in exchange for putting 1.8 million Dreamers on a path to citizenship.
The plan could break a months-long partisan stalemate centered around federal spending, but potential roadblocks and threats like the one Pelosi leveled Wednesday could drag out the disagreements.
She was speaking against a compromise federal budget deal recently announced by Senate leaders that would lift spending caps and avert a looming government shutdown - but that does not address the sensitive issue of immigration.More news: 1 deputy killed, 4 injured in Colorado Springs shooting
More news: Are US Troops in Iraq Staying or Going? Depends Who You Ask
More news: Colts make it official, hire Josh McDaniels as new coach
For hour after hour, Ms. Pelosi, 77, read heart-rending testimonies from Dreamers who had written their representatives about their lives. She applied for DACA status in 2012 and said she now works in health care. At one point, she suggested lawmakers should "just pray all day". But most sat skimming their phones or reading documents.
"Our plea to the speaker is for us, for ourselves, to honor the values of our founders", she continued. The Republican side of the chamber was virtually empty. "What's wrong, there's something wrong with this picture and that is why this morning, when we took a measure of our caucus on support for the package - well we have to see all the particulars of it yet but there are good things in it - that it does nothing to even advance, even with a commitment, without having passed the legislation first, to advance bipartisan legislation to protect Dreamers in this house", she said.
Pelosi's marathon speech was the longest on the House floor since at least 1909.
At any other time, House Democrats would have taken a domestic spending victory and moved on.
Historically, approval ratings that low have led to electoral disaster; in 2006, GDP growth of 2.7 percent was not enough to save Republican control of Congress.
But some Democrats now argue that the party should define and sell its own tax plan in a way that can win voters who are already optimistic about the economy.
Buck is one of Ryan's closest aides and has served on the Republican leader's staff since his failed vice presidential run alongside Mitt RomneyWillard (Mitt) Mitt RomneyDems pick up deep-red legislative seat in Missouri Pawlenty departing Wall Street group as campaign rumors swirl Trump ambassador nominee spread conspiracy theories about Cruz, Kasich MORE in 2012, according to his LinkedIn page.
"We're not going to bring immigration legislation through that the president doesn't support", Ryan told reporters at a Tuesday news conference.