FILE - U.S. Senator Kamala Harris launches her campaign for President of the United States at a rally at Frank H. Ogawa Plaza in her hometown of Oakland, California, Jan. 27, 2019.
FILE - U.S. Senator Kamala Harris launches her campaign for President of the United States at a rally in Oakland, California, Jan. 27, 2019.

WASHINGTON - Vanquished opponents of former U.S. Vice President Joe Biden are continuing to line up behind his bid for the Democratic presidential nomination as he heads to six more state primary elections on Tuesday against Vermont Sen. Bernie Sanders.

California Sen. Kamala Harris, who dropped out of the contest in December, endorsed Biden on Sunday, saying that she felt that he was best prepared to "steer America through these turbulent times."

Harris, often mentioned by U.S. political analysts as one of several possible vice-presidential running mates with Biden, said the U.S. needs a president "who reflects the decency and dignity of the American people, a president who speaks the truth; and a president who fights for those whose voices are too often overlooked or ignored."

Sanders, Biden Face off in Narrowed Race

She is the sixth former rival to endorse Biden, a list that also includes former South Bend, Indiana Mayor Pete Buttigieg and Minnesota Senator Amy Klobuchar, both of whom dropped out of the race for the Democratic presidential nomination just ahead of last week's Super Tuesday voting, when Biden won 10 of the 14 state party nominating elections over Sanders, a self-declared democratic socialist. After losing all 14 states to Biden, former New York Mayor Michael Bloomberg, after spending more than $500 million of his own money on his campaign, also endorsed him.

Biden praised Harris as a political figure who has "spent your whole career fighting for folks who've been written off and left behind."

Civil rights leader Jesse Jackson endorsed Sanders, saying that "with the exception of Native Americans, African Americans are the people who are most behind socially and economically in the United States and our needs are not moderate. A people far behind cannot catch up choosing the most moderate path."

"The most progressive social and economic path gives us the best chance to catch up and Sen. Bernie Sanders represents the most progressive path," Jackson said.

On Tuesday, Biden and Sanders face voters in Michigan, the auto-manufacturing hub in the U.S. and the state with the most delegates at stake this week to July's national Democratic presidential nominating convention. The fivethirtyeight.com political forecasting site is predicting that Biden will win 69 of the state's 125 pledged delegates to 56 for Sanders.

The fivethirtyeight site gives Sanders a slight edge in the western state of Washington, where 89 delegates are at stake, with Biden ahead in the Midwestern state of Missouri and the Southern state of Mississippi. Forecasters say the two candidates are virtually even in two smaller states, Idaho and North Dakota.

Just a week ago, before the Super Tuesday voting, the fivethirtyeight site was predicting that no Democratic candidate would be able to win the party nomination with a majority of delegates on the first convention ballot to face Republican President Donald Trump in November's national election.

Now, however, it predicts that Biden will cruise to victory on the first ballot, although neither Biden nor Sanders is close yet to a majority of delegates.

Sanders predicted on the "Fox News Sunday" show that he would win the Michigan vote.

"Joe Biden is a friend of mine," Sanders said. "Joe Biden is a decent guy."

But Sanders said the contest with Biden comes down to "which candidate is stronger in defeating Trump." He said he expects to win the key Michigan vote Tuesday and "certainly would not consider dropping out" if he loses.

"We won California, the biggest state in the country," Sanders said of last Tuesday's vote.

Sanders attacked Biden's vote as a senator for the American war in Iraq and trade deals with Canada and Mexico and another with Pacific Rim countries that Trump abandoned when he became president.

Biden and Sanders are scheduled to debate each other March 15.