US Democratic legislators on Wednesday chose House Speaker Nancy Pelosi to lead the party into the Joe Biden era and preside over their narrow House majority as the most powerful person in Congress. Ms Pelosi, 80 – the highest-ranking woman in US congressional history and outgoing President Donald Trump's nemesis on Capitol Hill – ran unopposed for the top job. She was nominated in an online leadership election, the first of its kind as the nation grapples with the coronavirus pandemic. "I'm thrilled, I'm excited, and I can't wait to be working with the new president of the United States, Joe Biden and [vice president] Kamala Harris," Ms Pelosi said. In accepting the nomination she pledged to take action to help crush the Covid-19 crisis and prioritise achieving justice for Americans on the issues of health care, economic security, the courts and climate change. Mr Biden called Ms Pelosi to congratulate her and say "he looks forward to working with her and Democratic leadership in the House on a shared agenda to get Covid-19 under control and build our economy back better", his transition team said. A formal House floor vote for the speakership occurs in January after the new congressional session begins, and shortly before Mr Biden takes office as president. She is widely expected to win. Ms Pelosi has led her caucus since 2003. Two years ago the veteran politician representing San Francisco agreed to serve in the post through 2022 at most, a move that cleared the way for her easy renomination. The House Democratic caucus, in a tweet, hailed the nomination of their "fearless leader". But tensions still simmer. In the November 3 election, Democrats fell well short of their stated aim to expand their 233-202 majority, failing to oust a single Republican incumbent and losing at least 10 seats. Some close races were still being counted, but when the dust settles Ms Pelosi will find she is leading with a reduced majority. Asked on Wednesday whether she would abide by her commitment to step down by late 2022, she said her earlier remarks stand. "I don't want to undermine any leverage I may have, but I made the statement," Ms Pelosi said. While there have been calls within the ranks for new blood on top of the ideologically fractured conference, the three chief positions went again to a trio of octogenarians led by Ms Pelosi. House majority leader Steny Hoyer, 81, and majority whip James Clyburn, 80, the highest ranking black member, were also re-elected.