With outgoing Speaker Paul Ryan yielding to the 78-year-old, she will again become the nation’s third most senior official and seal her reputation as one of the great survivors in American politics.

In her first stint, Pelosi was a strong opposing force to Republican George W. Bush in the final two years of his presidency.

Her role as a restraint on Trump would be similar.

But she will also need to keep the reins tight on her own caucus, some of whose newly empowered progressives are seeking swift punitive measures against Trump in the coming months.

She and the Democratic leadership would have the power to block Republican legislation, hamstringing large parts of Trump’s agenda ranging from proposed new tax cuts to building a wall on the border with Mexico.

And Pelosi could make life for Trump much harder if she uses subpoena power to compel administration officials to testify before Congress or turn over key documents, or if she launches impeachment proceedings.

So far, she has spoken out against using such a powerful political cudgel against him, arguing that the explosive step would likely mobilise Republican voters eager to protect the president.

In her reprised role, she will have to thread a political needle, standing up to Trump when needed but also showing that her party is capable of working with the president to pass legislation.

Her immediate task: finding a way to help end a stand-off over Trump’s border wall demand that has led to a partial government shutdown now stretching almost two weeks.

Three weeks earlier, at a remarkable Oval Office confrontation with cameras rolling, Pelosi showed she was not afraid to go toe to toe with Trump in a public forum when he appeared to belittle her effort to secure support for her speakership.

Shortly after leaving the meeting, Pelosi told a private gathering of fellow Democrats that the wall was a “like a manhood thing” for Trump, a comment seemingly calibrated to unnerve the president – and promptly and widely leaked to the media.

Nancy Pelosi privately disses Donald Trump’s ‘manhood’ after White House meeting

Pelosi is unquestionably among the savviest political leaders of her generation. She shepherded then president Barack Obama’s health law through the House to its contentious, historic passage in 2010.

Perhaps for that reason she is still seen by some as a liability eight years later, with Republicans presenting her as the ultimate liberal bogeywoman.

“Can you imagine Nancy Pelosi as speaker of the House?” Trump asked a crowd at a Minnesota rally in October.

“Don’t do that to me!”

Friends, family and foes, even those within her party who pressed for her to step aside for the next generation, praise her political skills.

“She’ll cut your head off, and you won’t even know you’re bleeding,” Pelosi’s daughter Alexandra said Wednesday on CNN.

Pelosi’s big comeback was no foregone conclusion. But she shrewdly navigated a simmering party power struggle that saw dozens of House Democrats and candidates signalling their desire for change at the top.

The internal resistance largely stems from Pelosi’s broad unpopularity among voters. But in an interview published Wednesday, she pushed back at the notion that she is reviled.

“I don’t necessarily feel hated. I feel respected,” she told Elle magazine.

“They wouldn’t come after me if I were not effective.”

At least in part, Pelosi’s reputation is shaped by years of rightwing attacks. Conservatives depict her, the wife of an investment millionaire from California, as the embodiment of a leftist elite.

She is accused of everything from wanting to raise taxes for middle-class families to supporting a massive influx of illegal immigrants.

US politics requires donning “a suit of armour” and the ability “to take a punch”, she has said.

Agence France-Presse, The Washington Post