The veteran California Democrat, who turns 78 next month, took the floor at 10:04 am (1504 GMT) and began to speak.
And she kept speaking. And speaking. And speaking.
Eight hours and seven minutes later, at 6:11 pm, she relinquished the floor — an entire work day standing at her desk in four-inch (10-centimeter) heels and consuming nothing but water, according to an aide.
It was a remarkable display of determination by the minority leader and former House speaker, which ended with her high-fiving Democratic colleagues who gave her a standing ovation.
“I just got word that the House historian confirms that you have now set the record for the longest continuous speech in the House since at least 1909,” said Pelosi during her marathon, reading aloud from a clerk’s message.
“I wonder what that was.”
That honor belonged to congressman Champ Clark of Missouri, who spoke for five hours and 15 minutes. It was unclear if any House floor speeches before 1909 had gone longer.
Pelosi 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 does not address immigration.
Pelosi said she would oppose the deal unless House Speaker Paul Ryan gave assurances he would bring immigration legislation to the floor for a vote.
Americans “need a solution to immigration, which is long overdue,” she said.
Pelosi was not violating House rules with her record-busting speech. Party leaders technically take the floor for one minute, but are allowed to speak for as long as they wish.
– ‘Moral cowardice’ –
At times she turned to scripture, and cited the biblical tale of the Good Samaritan.
She also read directly from statements by dozens of immigrants known as “Dreamers” — people who arrived in the United States illegally as children but were protected from deportation under president Barack Obama’s Deferred Action for Childhood Arrivals program.
In September President Donald Trump ended DACA, but gave Congress several months to craft a solution.
If Congress does not act by the March 5 deadline, some 1,000 immigrants per day could face deportation.
“Our Dreamers hang in limbo, with a cruel cloud of fear and uncertainty above them,” Pelosi said.
“The Republican moral cowardice must end.”
While the Republican side of the chamber was largely empty, dozens of Democrats trickled in to hear Pelosi, or sit behind their leader offering support.
“I’m proud to be here in solidarity with @NancyPelosi demanding action to #protectDreamers,” congresswoman Betty McCollum tweeted, using the hashtag #GoNancyGo.
“Take note, @realDonaldTrump: THIS is what true leadership looks like,” added House Democrat Gwen Moore.
Some Republicans signalled their displeasure with Pelosi eating up valuable floor time.
“Once again, Democrats are threatening to hold government funding & pay for our troops hostage over an unrelated issue,” House Republican Steve Pearce tweeted.
While impressive, Pelosi’s speech is far from the longest in congressional history.
That distinction goes to Senator Strom Thurmond of South Carolina, who in opposition to the Civil Rights Act of 1957 delivered an obstructive Senate speech known as a filibuster that lasted 24 hours and 18 minutes.
More recently, Senator Ted Cruz spoke for 21 hours and 18 minutes on the Senate floor in 2013, at one point reading from the Dr. Seuss children’s book “Green Eggs and Ham,” to oppose funding then-president Barack Obama’s health care reform law.
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