Transcript for 2020 candidates speak out about Michael Bloomberg's potential bid
Now to the race for 2020. Many democratic hopefuls hitting the campaign trail this weekend. But is a potential new opponent already shaking up the race? Rachel Scott is just back from Iowa. Reporter: With the first vote less than 90 days away, the democratic candidates for president are bracing for a shake-up. Billionaire Michael Bloomberg setting the stage to jump in the race. And the national early front-runner, former vice president Joe Biden, saying bring it on. I have no problem with him getting in the race. In terms of he's running because of me, the last polls that I looked at, I'm pretty far ahead. Reporter: Sources close to Bloomberg say he's worried that the current field of candidates won't be able to beat Donald Trump. And he thinks he can. But Progressives are criticizing the former New York City mayor for relying on his immense personal wealth to find a path to the nomination. I think that our elections should not be something that are bought by billionaires. Sorry, you ain't gonna buy this election. Reporter: This weekend, Vermont senator Bernie Sanders on a multistop swing through Iowa. Hello, Iowa! Reporter: Campaigning for the first time with congresswoman Alexandria ocasio-cortez, a key endorsement for his campaign. I sat down with the two of them and asked ocasio-cortez why she's supporting Sanders over senator Elizabeth Warren. It's about a personal story and a personal history, and I think the senator's history and commitment is unique. Reporter: And Sanders unleashed on the Bloomberg campaign plan to skip out on the earliest voting states -- Iowa, New Hampshire, South Carolina, and Nevada. When you're worth $50 billion, I guess you don't have to have town meetings, you don't have to talk to ordinary people. What you do is you take out, I guess a couple of billion dollars and you buy the state of California. Rachel, let's go back to Michael Bloomberg. If he jumps into this race, his campaign strategy is very unconventional. What are his aides telling you? Reporter: He knows the key early voting states are only a fraction of those that he needs. He also understands the rest of the democratic field has a head start. If he does get into this race, his advisers say they're confident he can win the states on super Tuesday and beyond. Rachel, thank you. And there's much more ahead on "World news tonight" this
This transcript has been automatically generated and may not be 100% accurate.