Bernie Sanders, the socialist senator who is challenging Hillary Clinton for the Democratic presidential nomination, said another billionaire entering the race would be "proof what I have been saying for a long time - this country is moving away from democracy to oligarchy". But they said Bloomberg has expressed concern about the damage caused by revelations she used a private email address and server while serving as secretary of state, and he fears she may emerge atop the Democratic field as a weakened nominee.

When Sanders was asked on NBC's Meet the Press about Bloomberg's candidacy, he called attention to one thing Bloomberg and Trump have in common: both are billionaire businessmen. He supposedly is willing to spend a billion dollars of his own money, but only, apparently, if the major parties nominate what he considers to be fringe candidates: Bernie Sanders and either Donald Trump or Ted Cruz.

Mr Trump, 69, said: "I would love it. I know Michael very well, I'd love to compete against Michael".

"I am a conservative", Trump, endorsed this week by 2008 vice presidential candidate Sarah Palin, said on NBC.

Morning Consult found that in a national race involving Sanders, Trump and Bloomberg, Sanders would take 35% of the vote, Trump 34% and Bloomberg 12%.

The news this weekend that former New York Mayor Michael Bloomberg might get into the presidential race is creating ripples on the campaign trail.

The 73-year-old Bloomberg served three terms as the mayor of the biggest USA city and, since leaving office two years ago, has unsuccessfully sought to win support for tighter gun control laws in the U.S. Bloomberg has told allies he would likely mount a bid if either Trump or Texas Sen. Bloomberg has reportedly told his allies that if Trump or Sen. But Michael has been a friend of mine. He's very opposite of me on guns and he's opposite on pro-life.

Joshua Lott/Getty Images Republican presidential candidate Donald Trump speaks during a campaign event in Pella, Iowa.

Sure, you can argue that some Republicans might vote for Bloomberg, but realistically, the fact that Bloomberg has become the target of the NRA political attack machine and that he has championed Abortion rights and limiting the size of soft drinks for purchase in NY city absolutely goes counter to Republican/Conservative ideology. She said Sunday that she'll "relieve" him of that decision by winning the nomination.