David Axelrod actually said...

But I -- you know, it's been interesting to see. He's been -- Klobuchar, Buttigieg, they've been reluctant to go right at Biden.

If you don't pick me, it could be him. And he's not going to be able to beat Donald Trump because he's too far out on the left.

There are constitutionally shared powers here, that Congress does have responsibilities and they ought to be treated with respect.

He could not refrain from taking shots at his predecessors, and particularly, President Obama.