NEW YORK — Former Massachusetts governor Deval Patrick formally announced on Thursday that he is entering the 2020 presidential race, bloating an already crowded field.

Patrick, one of the first US African-American governors, announced his presidential bid in a 2:35 minute video posted on his website.

"In a spirit of profound gratitude for all the country has given to me, with a determination to build a better, more sustainable, more inclusive American Dream for everyone: I am today announcing my candidacy for President of the United States," Patrick says in the video. He tweeted the same message.

The entry of Patrick, who becomes the 18th candidate in the 2020 Democratic race, highlights anxieties among party centrists who fear that the left-wing policies of Elizabeth Warren and Bernie Sanders will damage the Democrats' chances of beating President Donald Trump next year.

Patrick had earlier ruled out a bid in December 2018 but reportedly regretted the decision.

Former New York mayor Bloomberg took a formal step towards joining the Democratic presidential race on Tuesday when he submitted paperwork to be on the ballot in Arkansas, four days after doing the same in Alabama.

Both states have early deadlines to register for the primaries, which Patrick has missed.

Bloomberg, who like Trump is a septuagenarian white New York billionaire, has yet to officially declare that he is running for the White House.

Experts say a Bloomberg candidacy could hurt the current front-runner Joe Biden, the former vice president who is the leading centrist in the race.

It is unclear what sort of impact Patrick's entry less than three months before the first votes in Iowa might have.

Patrick was a two-term governor of Massachusetts from January 2007 to January 2015.

The Democratic contest has two black candidates, Senator Kamala Harris of California and New Jersey Senator Cory Booker. Both are languishing in the polls. — AFP