WASHINGTON • United States Senator Bernie Sanders, the progressive populist who mounted a fierce challenge to front-runner Hillary Clinton in the 2016 White House campaign, said yesterday he will again seek the Democratic Party's presidential nomination in 2020.

Mr Sanders, the 77-year-old independent senator from Vermont, said one of his primary motivations is to oust President Donald Trump, who beat Mrs Clinton in that election.

"I think the current occupant of the White House is an embarrassment to our country," he said in an interview with Vermont Public Radio.

"I think he is a pathological liar... I also think he is a racist, a sexist, a homophobe, a xenophobe, somebody who is gaining cheap political points by trying to pick on minorities, often undocumented immigrants."

Mr Sanders upended the party establishment three years ago by siphoning support from the Democrats' liberal wing and young people, touching off a leftist movement that ushered progressives like freshman Representative Alexandria Ocasio-Cortez into office in the November mid-term elections.

Mr Sanders starts his 2020 campaign with a long list of potential advantages, including a massive e-mail list of supporters, a proven track record of small-dollar fund-raising and veteran aides who helped chart a path to victory in key states like New Hampshire.

In an e-mail to supporters yesterday, he pledged to build a vast grassroots movement to confront the special interests that he said dominate government and politics.

Mr Sanders said he would push for many of the same issues that powered his 2016 bid, including universal healthcare, raising the minimum wage and free public college tuition.

"Our campaign is about creating a government and economy that works for the many, not just the few," he said in the e-mail, asking for one million people to sign up to start the effort.

But 2020 will be a very different campaign cycle.

Many former Sanders supporters and aides are looking at other options in a diverse field of Democrats that could top 20 well-known names.

Several Democrats already are echoing his economic message at a time when the party is increasingly relying on a voting base made up of women, minorities and young people. In a year when Democratic voters have signalled an increased desire for racial and gender diversity, Mr Sanders would be only the second straight, white man in the field.

BLOOMBERG, REUTERS