But Reid, who served as a Democrat in the U.S. Senate for 30 years, including as majority leader for eight years, said it didn't matter which candidate comes out in support of Sanders' signature health care plan: "I’m against it."

"It’s impractical ... There’s not a chance in hell it would pass," he told ABC News Political Director Rick Klein, instead advocating for strengthening the Affordable Care Act -- or Obamacare -- and looking to pass a public option.

“A Bloomberg campaign non-disclosure agreement obtained by The Nation contains language that could prevent staffers from reporting workplace abuse.”

“The NDA totals 9 pages and forbids employees from discussing ‘any and all non-public information’ and ‘activities’ by the campaign.”

“And while it’s understandable that a campaign would want to keep things like internal polling under wraps, transparency advocates say that the NDA is overly broad to the point of preventing sexual harassment, as well as other forms of workplace abuse like racial discrimination, from being reported.”

“Bernie Sanders got so close to running a primary challenge to President Barack Obama that Senator Harry Reid had to intervene to stop him.”

“It took Reid two conversations over the summer of 2011 to get Sanders to scrap the idea.”

“That summer, Sanders privately discussed a potential primary challenge to Obama with several people, including Patrick Leahy, his fellow Vermont senator. Leahy, alarmed, warned Jim Messina, Obama’s presidential reelection-campaign manager… David Plouffe, another Obama strategist, confirmed Messina’s account, as did another person familiar with what happened.”

Former President Barack Obama has declined to endorse in the 2020 Democratic primary, though several White House hopefuls have sought his advice. That hasn't stopped candidates, like his former Vice President Joe Biden, from touting their connections to the popular Democrat.

But Michael Bloomberg's latest ads are raising eyebrows among Obama administration alumni, who say the spots mislead viewers into thinking the former president has endorsed him.

Bloomberg's new 30-second video entitled "Difference" strings together photos of the two politicians and several clips of Obama praising Bloomberg in an effort to appeal Obama's supporters in the Democratic electorate.

That advertisement, as well as the similar "Steady Leadership" that debuted in early February, feature swelling music, soaring praise, and photos of two politicians side by side. But it doesn't paint an entirely accurate picture of Bloomberg and Obama's relationship, former top aides say.

"They certainly weren't best buds," Obama's former senior advisor David Axelrod told the Wall Street Journal. "It does speak to the power of Obama with Democrats. Everyone wants to have an ad like this."