Well, he thought Roe went to far, voted to let the states overturn Roe (which is fucking weird on several levels beyond just the politics of abortion) authored large segments of the crime bill, sponsored the RAVE act...
I guess we can imagine he suddenly changed all of his opinions on these things after a lot of personal introspection and self reflection. It's not like he's an especially proud man who won't ever admit fault... nevermind that he's said that he has no regrets about any decision he's made and he refuses to apologize about anything.
I'm sure he'll be a fine candidate that absolutely won't depress engagement or turnout and certainly won't be fuel for the fire of another decades of "both sides!" memes and his charming personality and ardor for a good smelling head of hair will sell itself.
Democrats have nothing to worry about nominating this guy.