@JPB,
JPB wrote:I'm thinking the best thing to do is keep the few moderate Republicans we have right where they are.
That's what I said about Alan Specter when Pennsylvania Democrats nominated Pat Toomey over him. Back then, joefromchicago countered (and I paraphrase) that keeping moderate conservatives in the Senate is the Republicans' job, not the Democrats'. On reflection, I think he was right.
I don't know if Elizabeth Warren could beat Scott Brown. But I do wish her luck in trying.