David Weigel points out that Republican Senate candidates are leading in the polls in every state Mitt Romney carried, but aren’t ahead in any blue state except Maine (where Republican Susan Collins is an incumbent). That’s enough to give Republicans control of the Senate.

Amy Walter, meanwhile, asks a question about the Republican weakness in blue states.

Republicans have everything going for them in 2014. If the combination of a great environment, lower turn-out, and good candidates can’t get them to victory in swing states like Colorado or Iowa, it doesn’t bode well for a GOP presidential candidate in 2016.

I’d add Michigan to that list. But I wouldn’t rule out a Republican victory in any of them.