"We take a big risk if we replace one arrogant billionaire with another," said Massachusetts Senator Elizabeth Warren at the opening of the debate ahead of the Democratic nomination meetings in Nevada on Saturday.

For the first time, former New York mayor, as well as billionaire, Mike Bloomberg is participating.

Attacks on Bloomberg

On stage in Las Vegas, he is joined by Vermont Senator Bernie Sanders, former South Bend Mayor Pete Buttigieg, Executive Vice President Joe Biden, Massachusetts Senator Elizabeth Warren and Minnesota Senator Amy Klobuchar.

And directly, as expected, was a lot about attacks on Bloomberg.

"Stop and fresh"

It began with Vermont Senator Bernie Sanders bringing up the so-called "stop and fresh" procedure during Bloomberg's time as New York mayor, which allowed police to stop people and search them on very vague grounds.

- I'll tell you who we are competing against - a billionaire who calls women for thick women's timber and lesbians with horse faces. No, I'm not talking about Donald Trump, I'm talking about Mayor Bloomberg, Elizabeth Warren said.