Rep. Steve King, a hard-liner, has publicly mulled a bid and would probably clear the GOP field if he ran. The general election would be competitive, but not nearly as GOP-friendly as with a more moderate candidate such as Rep. Tom Latham, who said last month he wouldn’t seek the Senate seat.

Recruiting broadly popular candidates, and fending off the party’s most conservative elements, is critical, especially in states such as Michigan if Sen. Carl Levin retires. (He’s said he’ll decide in the coming weeks.) If he does, the Wolverine State joins Iowa as a prime pickup opportunity.

That doesn’t mean Republicans will have a cakewalk in any of these states. The party lacks obvious, strong candidates for targets such as Colorado and New Mexico. In New Hampshire, Shaheen is formidable: One recent poll reported her favorability near 60 percent. Minnesota remains solidly blue even if Franken won by only a few hundred votes in 2008. And few think Democratic Sen. Mark Warner will even face a legitimate challenger in Virginia. Democrats remain confident that Republicans will fumble attempts to recruit the kind of candidate necessary to put all of them in play.

The NRSC doesn’t need to make every state competitive to be successful. The goal instead is to put Democrats on their heels in two or three. At worst, that would force Democrats to siphon money and time away from their red-state beachheads. And maybe, especially in one of the open races, Republicans can pull an upset. Because they’ll need it: Just focusing on the red states will likely leave them short.