A Democratic US lawmaker shattered a record for the longest speech in Senate history Tuesday, staying on his feet for more than 25 hours to deliver a fiery protest against President Donald Trump's "unconstitutional" actions.

Senator Cory Booker's display of endurance -- to hold the floor he had to remain standing and could not even go to the bathroom — recalled the famous scene in Frank Capra's 1939 film classic "Mr. Smith Goes to Washington."

The longest Senate speech on record before Tuesday was delivered by South Carolina's Strom Thurmond, who filibustered for 24 hours and 18 minutes against the Civil Rights Act of 1957.

Booker, only the fourth Black senator to be popularly elected to the body, blew past that deadline, his voice still strong but emotional as he topped out at 25 hours and five minutes.

"Strom Thurmond's record always... really irked me," he later told broadcaster MSNBC.

"That the longest speech on our great Senate floor was someone who was trying to stop people like me from being in the Senate."

The public galleries of the Senate chamber gradually filled as the moment he broke the record approached, with more Democratic lawmakers joining the session — although Republicans largely stayed away.

"This is a moral moment. It's not left or right. It's right or wrong," Booker said as he wrapped up.

He also quoted his mentor John Lewis, a 1960s civil rights movement leader, who urged campaigners to get into "good trouble," before finally pronouncing "Madam President, I yield the floor."

The 55-year-old New Jersey native had found a moment for some humor as he passed the record, joking: "I want to go a little bit past this and then I'm going to deal with some of the biological urgencies I'm feeling."

'Foundations of democracy'

Although Booker's talk-a-thon was not actually blocking the majority Republican Party from holding votes in the Senate, as would be the case in a true filibuster, his defiance quickly became a rallying point for beleaguered Democrats.

Booker, a former presidential candidate, seized command in the chamber at 7:00 pm (2300 GMT) Monday and finished at 8:05 pm Tuesday.

He lashed out at Trump's radical cost-cutting policies that have seen his top advisor Elon Musk, the world's richest person, slash entire government programs without consent from Congress.

The senator said Trump's aggressive seizing of ever-more executive power had put US democracy at risk.

"Unnecessary hardships are being borne by Americans of all backgrounds. And institutions which are special in America, which are precious and which are unique in our country, are being recklessly — and I would say even unconstitutionally — affected, attacked, even shattered," Booker said.

"In just 71 days the president of the United States has inflicted so much harm on Americans' safety, financial stability, the core foundations of our democracy," he said.

But he had words of encouragement for Trump opponents, saying as he concluded that "the power of the people is greater than the people in power."

Cramps and sore throat

Booker later went into detail about how he withstood the physical demands of the speech.

"My strategy was to stop eating. I think I stopped eating Friday and then to stop drinking the night before I started on Monday," he told reporters in the Capitol.

The approach "had its benefits and had its really downsides... different muscle groups start to really cramp up" with dehydration, he added.

In a statement sent by his office, Booker added that he was "tired and a little hoarse."

Democratic lawmakers, in the minority in both the Senate and House of Representatives, have struggled over how to blunt Trump's efforts to downsize government, ramp up deportations and shred much of the country's political norms.

"I just want to thank you for holding vigil for this country all night," Senator Raphael Warnock told Booker on the floor.

Booker dedicated much of his speech to criticizing Trump's policies, but to pass the time he also recited poetry, discussed sports and entertained questions from colleagues.

"If you love your neighbor, if you love this country, show your love. Stop them from doing what they're trying to (do)," he said.

(Source: Michael Mathes, AFP)