One of the running themes of this sucky blog is much of what is generally described as the "political center" is not and "moderate politicians" are not. Such "centrism" is mostly about issues and votes which have no constituency where Democrats are willing to join with Republicans (yay, bipartisan!). Or, at least, no constituency of voters. They're things which, usually, have a constituency of big donors. They aren't our principled deal-making "last honest people of Washington." They're our most corrupt.
Thinking otherwise allows corrupt Dems to join with equally corrupt Republicans to do things like this, and con people into thinking it's about "principled moderation" and that (in some cases) they're just representing their red state voters. Crazy liberals can't win in Missouri! Only principled moderates can!
No voters in Missouri want to eviscerate banking reforms. The most you can say with respect to electoral viability is that by pleasing big money, you prevent big money from going after you at election time. That might be true. But that's because they're going to run ads about other issues (the laundry list of Liberals Are Bad), not because supporting bank regulations is going to turn off independent minded swing voters.
I question the utility of being squishy on abortion rights and gun control, but it's fair to say that positioning might actually get some votes. Voting for future bank bailouts? Nah.