Transcript for Michael Bloomberg takes step toward 2020 bid
We move to that bombshell announcement in the race for the white house. There you see billionaire Michael Bloomberg, the former mayor of New York, is taking a major step this morning towards launching a bid for the democratic nomination, a move that could scramble the race and linsey Davis has the story. Good morning, linsey. Reporter: Hey, good morning to you, George. Michael Bloomberg is reportedly worth an estimated $52 billion. He has built an empire including this building right behind me and now this latest move seems to be an indication that he's not quite sure any of the current democratic candidates can get the job done against president trump. An adviser to Bloomberg says Mike believes that Donald Trump represents an unprecedented threat to our nation, adding that Mike is increasingly concerned that the current field of candidates is not well positioned to defeat the president. I'm a new Yorker. And I know a con when I see one. Reporter: Bloomberg took on trump at the democratic national convention in 2016 and he's getting ready to do it again. The bottom line is, trump is a risky, reckless and radical choice and we can't afford to make that choice. Reporter: This after the 77-year-old shot down the possibility of a run earlier this year when Joe Biden entered the race. His future rivals reacting swiftly on social media and in interviews. Senator Elizabeth Warren tweeting, welcome to the race, Mike Bloomberg and Bernie Sanders writing, the billionaire class is scared and they should be scared. We already have one billionaire in the race and seeing the limits of what money can do. Reporter: Bloomberg is reportedly the 14th richest person in the world. He left the democratic party in 2001 to run as a Republican for mayor of New York City going on to serve three terms. Last year the billionaire made it official announcing on Instagram that he was reregistering as a Democrat saying we need Democrats to provide the checks and balance our nation so badly needs. Bloomberg previously said he would only get into the race if he thought he had a reasonable shot at winning. George. Okay, linsey, thanks very much. Let's bring in Matthew dowd and linsey said it right there, Bloomberg in the past said he'd only get in if he thought he had a reasonable shot at winning looking at this field and saying, maybe I have a chance. Well, I think that's the billion dollar question and this is an unexpected guest at the Christmas party at one of the richest people in the world advocated out of climate change and guns important to the democratic constituency but I'm still not convinced there is a spot for him in the party because 75% of the voters in the democratic primary say they're satisfied with the field so we'll have to see if he does get in and what kind of reception he's going to get. Especially, George, in places like where I am in new Hampshire. And who it hurts and helps. We know that he passed on a race before when he thought Biden was doing well and uncomfortable with a lot of Elizabeth Warren's positions. The question is will it hurt her or help her if he gets in? Reporter: Well, I think this is the biggest indictment of Joe Biden. He would not have gotten in or considered getting in if he thought Joe Biden was problematic there. I think this helps Elizabeth Warren. It allows her to pivot against a billionaire which she's been pivoting against wealthy people throughout the race and begins to even more divide the center part of the field. I also think it hurts Pete buttigieg, the mayor of south Bend, Indiana who consolidated some of the central support. Who know what is it could do. It could help Elizabeth Warren but it will certainly, certainly disrupt this field. Yeah, the question is if he does get in, can he actually get the nomination? Can a billionaire in this environment get the democratic nomination? I think that's incredibly problematic. I mean, in the way the field has rolled out, the way that issues are in the democratic primary today, and keep this in mind, George, he looks like he's going to self-finance so he may never even get in a debate.
This transcript has been automatically generated and may not be 100% accurate.