Washington CNN  — 

Democratic presidential candidate Sen. Amy Klobuchar on Sunday joined others vying for the party’s nomination in taking issue with Michael Bloomberg’s potential 2020 bid and criticizing the former New York City mayor’s billionaire status.

“And when people look at the White House and they see this multi-millionaire (President Donald Trump), including, by the way, independents, moderate Republicans, and how now he’s messing up so many things, I don’t think they say, ‘Oh, we need someone richer.’ I don’t think that, Jake. I think you have to earn votes and not buy them,” Klobuchar told CNN’s Jake Tapper on “State of the Union,” adding to the lukewarm reception given in recent days to the billionaire politician by members of the crowded field of candidates.

Bloomberg, who had said in March that he wouldn’t run for president, filed Friday to run in Alabama’s Democratic presidential primary in 2020. He also plans to file in Arkansas’ Democratic primary before the state’s Tuesday deadline, Bloomberg spokesman Howard Wolfson told CNN last week.

The move is the clearest sign to date that the former three-term mayor is seriously considering following through with something he has been weighing for weeks. Bloomberg, whose media empire helped him amass a net worth of $51 billion, is the 8th richest person in America, according to Forbes. (Trump is 275th on that list, with an estimated net worth of $3.1 billion.)

Klobuchar said Sunday that she welcomes the former mayor into the contest, noting that he has done “incredible work” on gun safety and environmental issues. But the Minnesota Democrat also told Tapper that she doesn’t think Bloomberg can “just waltz in” and say, “I’m good enough to be president” and that “the other people aren’t good enough.”

Wolfson did not respond to CNN’s request for comment on Sunday about Klobuchar’s remarks.

‘You ain’t gonna buy this election’

Vermont Sen. Bernie Sanders, whose attacks on billionaires have been a hallmark of his campaign, weighed in on Bloomberg’s potential run Saturday during a campaign event in Iowa, saying, “Tonight we say to Michael Bloomberg and other billionaires: Sorry you ain’t gonna buy this election.”

“You’re not going to get elected president by avoiding Iowa, by avoiding New Hampshire, South Carolina and Nevada. You’re not going to buy this election by spending hundreds of millions of dollars on media in California. Those days are gone,” said Sanders, whose proposed tax plans on the wealthy would significantly reduce the number of billionaires in the country.

Sen. Elizabeth Warren was more welcoming of Bloomberg’s entrance into the fray than Sanders, with whom she is in a close race among likely voters in the key primary state of New Hampshire.

“Anyone’s welcome, that’s what a democracy is about,” the Massachusetts Democrat said at a campaign town hall on Saturday in Goose Creek, South Carolina, when asked about Bloomberg filing.

“Look, to me this isn’t about politics, this is about democracy. I’m here doing town halls in South Carolina because I want to be here. I think that our elections should not be something bought by billionaires, whether they’re reaching into their own pockets or whether they’re sucking up to the billionaires who can fund political action committees or make big donations,” Warren said.

Businessman Andrew Yang also offered a dubious analysis of Bloomberg’s prospects should he enter the race, saying Friday that “it’s going to be very, very difficult for him to jump in right now” and use ad buys in place of conversations other candidates have had with voters around the country.

“There are limits to what money can do,” Yang said during an interview on CNN Friday before Bloomberg filed to participate in the Alabama primary.

Meanwhile, former Vice President Joe Biden, whose campaign is struggling to break out of the Democratic field, encouraged Bloomberg to run – but also added he would “beat him like a drum.”

“I think he should jump in the race. He’s a good guy. He’s done a lot of good. And let’s see what happens,” Biden said in a Friday interview with CNN prior to Bloomberg’s filing.

“Every single poll that’s run I beat him like a drum as I said. And states in the South and states in the Midwest. And so look, if he wants to run he should just get in and run,” he said.

And billionaire Tom Steyer, who has stood out in the race as an ultra-wealthy financier who has used his own cash in an effort to win the White House, released a statement on Friday –also prior to Bloomberg’s filing – saying the former mayor must support a wealth tax if he wants to compete for the Democratic nomination.

“If Michael Bloomberg decides to support a wealth tax, I welcome him to this race. If not, it’s very clear that he should not be the Democratic nominee,” Steyer said. “We cannot afford to have a Democratic nominee in 2020 who does not support asking the wealthy to pay more to address the enormous inequality in our society.”

CNN’s Steve Brusk, Dan Merica and Chris Cillizza contributed to this story