When Nancy Pelosi stunned the world by ripping up Donald Trump's speech to Congress in 2020, the veteran lawmaker cemented the no-nonsense leadership style that made her perhaps the most effective US House speaker in history.

The longtime leader of Democrats in Washington has been a master strategist in the role, chastening the unbridled Trump and twice leading his impeachment, but also shepherding historic legislation as she navigated America's bitter partisan divide.

As Pelosi announced she would be standing down from the leadership when Republicans take over the lower chamber, allies hailed her achievements as its first -- and so far only -- female speaker, while foes cheered her exit.

But there is little doubt the 82-year-old Californian has left an extraordinary mark over a career that established her as one of the most powerful, and polarizing, figures in American politics.

As a child, "never would I have thought that someday I would go from homemaker to House speaker," Pelosi told fellow lawmakers Thursday, drawing applause from both sides of the aisle.

Come January, she said, it will be time to let "a new generation" take the reins.

San Francisco liberal

A San Francisco liberal and multimillionaire, Pelosi is far from universally popular.

She has long been a hate figure for the right -- an animosity that seemed to reach shocking new levels when an intruder, apparently looking for the speaker, violently assaulted her husband in the runup to the November 8 midterms.

During the deadly 2021 assault on the US Capitol, supporters of then-president Trump ransacked her office, and a crowd baying for blood chanted "Where's Nancy?" as they desecrated the halls of Congress.

The violence came after Trump refused to admit defeat and urged a rally to march on the Capitol to stop the certification of Joe Biden's win.

Pelosi moved quickly after that to try to oust the man she called the "deranged, unhinged, dangerous president of the United States."

Corralling Democrats with the tight grip she maintained on the party for two decades, she secured a second impeachment of the president days before he left office.

For as speaker, Pelosi was nothing if not effective.

She was instrumental in passing then-president Barack Obama's key health care reforms as well as massive economic packages after both the 2008 financial crisis and the Covid-19 pandemic.

Pelosi's goal may have been partisan but she succeeded thanks to cold-eyed realism, including working when needed with then-president George W. Bush even while fiercely opposing his invasion of Iraq.

Supporters believe she was vindicated on her anti-war stance and she was rewarded in 2007 when Democrats reclaimed the House and elected her speaker, making her the highest-ranking woman in US history until the inauguration of Vice President Kamala Harris in 2021.

"I want women to see that you do not get pushed around. You don't run away from the fight," Pelosi said in a 2018 interview -- the year before she began her second term as speaker.

"If you're effective as a woman, then they have to undermine you, because that's a real threat."

The one congressional job mentioned in the Constitution, the prestigious speaker position brings almost unfettered control over the day-to-day legislative process.

Pelosi had resisted Democratic calls to impeach Trump, the first time around, fearing the effects of overreach.

But she felt she had no choice after he was caught holding up US aid to Ukraine as he pressed a conspiracy theory about Biden.

That impeachment in 2019 poisoned her relationship with Trump, and as he wrapped up his State of the Union address later in the House chamber, Pelosi coolly tore up his speech -- in an image that went instantly around the world.

Pelosi has often hit back at Trump rhetorically, and was captured on video reacting furiously to suggestions he might join his supporters during the Capitol insurrection.

"If he comes, I'm going to punch him out. I've been waiting for this," she seethed.

"For trespassing on the Capitol grounds, I'm going to punch him out. And I'm going to go to jail, and I'm going to be happy."

Steeped in politics

The granddaughter of Italian immigrants, Pelosi was born in Baltimore where her father, Thomas D'Alesandro, was a mayor and congressman who schooled her in "retail politics" from a young age and staunchly backed Franklin Roosevelt's New Deal.

Pelosi has said her family taught her two political lessons. "One is to know how to count -- count your votes to win the election. The other is listen to your constituents."

Pelosi attended her first Democratic National Convention before hitting her teens and was pictured with John F. Kennedy at his inaugural ball when she was 20.

She moved to San Francisco and raised five children with businessman Paul Pelosi while delving into Democratic politics before being elected to Congress at age 47.

Taking up causes important to a city with major LGBTQ and Asian-American communities, she fought to fund AIDS research and pressed human rights in China.

She remains a vocal ally of Tibet's spiritual leader the Dalai Lama and won eternal antipathy from China's communist leaders when, on a 1991 visit, she defiantly unfurled a banner in Tiananmen Square honoring pro-democracy students killed in a crushed uprising.

While easily reelected to Congress every two years, the self-styled "mother, grandmother, dark chocolate connoisseur" became seen as a centrist by the standards of proudly left-wing San Francisco as she sought legislative compromise.

She will be stepping down at the end of a vexed congressional session in which she struggled to keep a lid on infighting between moderate and progressive Democrats.

This year she still managed to burnish her political legacy with a controversial trip to Taiwan -- amid warnings from Beijing of "serious consequences."

Defending the visit, she asked Americans to protect democracy worldwide and "make clear that we never give in to autocrats."

And in her outgoing speech, Pelosi aimed once last barb at her presidential adversary. Saying she has "enjoyed working with three presidents," Pelosi named George W. Bush, Obama and Biden -- but left out Trump.

© Agence France-Presse