If "safe" is your main concern, forget about Biden. The safest bet to beat Trump would be Klobuchar,

[MineralMan]

32. I like Amy Klobuchar very much. I've met and talked with her.

She's one of my Senators. However, if she were going to make a splash in this primary campaign, we'd be seeing some sign of that already. No sign; no chance of being the nominee.

In many areas, she's very progressive, but she will not be seen as a progressive by lots of Democrats. Always eager to communicate with her Republican colleagues in the Senate, she manages to get things done through cooperation, but that will be seen as a flaw by many Democrats.

She's a wonderful person, an excellent Senator for Minnesota, but is very, very unlikely to inspire broad national support strong enough to make her the presidential nominee for the Democratic Party.

As a nominee, she would be safe enough for Trump to win for name recognition reasons, I'm afraid.