Biden wins backing of ex-rivals Buttigieg, Klobuchar

Democratic presidential candidate Joe Biden enjoyed a boost on Monday, when rival Senator Amy Klobuchar announced she would suspend her campaign and throw her support behind the former vice president.

He also won the backing of former South Bend Mayor Pete Buttigieg, who quit the race a day earlier.

The Biden endorsements came on the eve of Super Tuesday, when 14 states hold nominating contests.

And with his former rivals rallying behind him and his weekend victory in South Carolina to overtake the current front-runner, Vermont Senator Bernie Sanders.

(SOUNDBITE) (English) U.S. DEMOCRACTIC PRESIDENTIAL CANDIDATE JOE BIDEN, SAYING:

"The pundits declared my campaign dead. But then along came South Carolina (crowd applause). And South Carolina had something to say about it. As I stand here today, because of the minority communities, I am very much alive because of you."

Biden's blowout win in South Carolina came courtesy of that state's majority African-American Democratic electorate.

And delivered on his promise that he could compete - and potentially win - in the large and diverse Super Tuesday states of Virginia, Texas, and the biggest of them all: California.

(SOUNDBITE) (English) U.S. DEMOCRATIC PRESIDENTIAL CANDIDATE BERNIE SANDERS, SAYING:

"The candidate who wins here in California, will likely be the Democratic nominee."

But Biden will need to get out from behind Bernie. Sanders rallied crowds in San Jose Sunday night.

And he touted the enthusiasm of his supporters.

(SOUNDBITE) (English) U.S. DEMOCRATIC PRESIDENTIAL CANDIDATE BERNIE SANDERS, SAYING:

"Right now here in California, our people have knocked on one million doors. That's what's going on all over this county."

But the self-proclaimed democratic socialist's second-place finish in South Carolina showcased a weakness among African-American voters, a core Democratic voting bloc.

Pressed about Biden's victory, Sanders said this:

(SOUNDBITE) (English) EXCHANGE BETWEEN U.S. DEMOCRATIC PRESIDENTIAL CANDIDATE BERNIE SANDERS AND REPORTER:

SANDERS: "We're doing really well with the African-American voters, you may know. I think there's some polls out there which suggested that we're actually ahead of him, nationally.

REPORTER: "But he won-"

SANDERS "-Yeah, I understand that he won, (laughs) I got that. But I think nationally, we're doing very well with the African-American vote, and i think you're going to see that on Super Tuesday."

Tuesday will also be the first real test of billionaire Michael Bloomberg's candidacy and his unprecedented spending.

The former New York City mayor has already spent more on television ads than Donald Trump and Democratic nominee Hillary Clinton did in their entire 2016 campaigns.

But if Bloomberg bet that so-called moderates, spooked by the progressive agendas of Sanders might coalesce around a single candidate, it's looking less likely that that candidate will be him.

None of the Democrats who've so far dropped out of the race have endorsed the former mayor.