Joe Biden has a reputation for saying what's on his mind, and on Thursday night, he reportedly didn't hold back about former Democratic presidential candidate Hillary Clinton.

"I never thought she was a great candidate. I thought I was a great candidate," the former vice president reportedly told an audience of hedge fund managers at the annual Skybridge Alternatives (SALT) conference in Las Vegas.

"No man or woman should announce for the presidency unless they genuinely believe that for that moment in the nation's history, they are the most qualified person to deal with the issues facing the country," Biden continued, according to TheStreet's Ronald Orol.

Despite his criticism of candidate Clinton, Biden said he thought she would have been "a really good president."

Biden had considered running for the Democratic nomination against Clinton and Sen. Bernie Sanders in 2016, but decided against it after the death of his son, Beau, in 2015. Biden has repeatedly said his emphasis now is on his family being "put back together," but on Thursday, he left the door open about a possible run in 2020.

"If I get those things done, and I'm healthy and viable, and it looks like I'm the best man to do it, I may very well do it," Biden said. "But my family comes first."

"Could I? Yes," Biden continued. "Would I? Probably not."

This isn't the first time Biden has spoken with regret about the 2016 election. In March, he told students at Colgate University in New York state that he thought he could have won the election against Donald Trump.

"I had a lot of data and I was fairly confident that if I were the Democratic Party's nominee, I had a better-than-even chance of becoming president," Biden said.

Biden isn't alone in thinking he could have beaten Trump.

"If Joe Biden would have run against Donald Trump, Biden would have won in a landslide," Republican Sen. Ben Sasse of Nebraska told the New York Times in April, noting that Trump won largely because of "who his opponent was."

Biden would be nearly 78 in 2020. At age 70, President Trump is the oldest president to  assume office.