When Republicans talk about the Senate sweep they might win in 2014, they put a few races in the "easy" column. They fully expect the open Senate seats in South Dakota and West Virginia, now held by Democrats, to go to the GOP. They're incredibly optimistic about the races in Alaska and North Carolina, where they have so far held off primary challenges from unelectable candidates. (Joe Miller, who won the 2010 GOP primary there but lost when Sen. Lisa Murkowski staged a November write-in campaign, is stuck in third place now.) In Louisiana they're running members of the House with great resumes—a doctor in Louisiana, an Iraq/Afghanistan veteran in Arkansas. And they can't say enough about Arkansas Rep. Tom Cotton, who won his House seat in November 2012 and was running for Senate nine months later.

But Arkansas is not cooperating with the plan, not yet. Republicans are currently being irritated by an NBC News/Marist poll that shows Cotton down 10 points to Sen. Mark Pryor. It's easy (and not wrong!) to point out that this is a poll of registered, not likely, voters, and that as the election approaches the electorate will change. But it's the second double-digit Pryor lead they've had to debunk in a month, and currently the senator leads Cotton right outside the margin of error, by about 5 points on average. The same registered voters who give Pryor a lead give Barack Obama a 34 percent approval rating—realistic, in a state he lost by 24 points—and favor former Rep. Asa Hutchinson for governor.

More worringly, Pryor remains pretty well-liked. He's got a 50–34 favorable rating, compared with 38–39 for Cotton. This contradicts one of the theories that Republicans have glommed onto for 2014, that they've invested early to weaken Democrats and back their best candidates. It's been 15 months, just a few weeks after Obama's second inauguration, since the Club for Growth ran this negative ad against Pryor.

A month later the Club for Growth reported its own internal polling that showed Pryor's support cratering, down 28 net points since the ad ran. To date, according to a Democrat familiar with Arkansas ad buys, GOP-aligned groups have spent $5.3 million in the state this cycle, and Democrats have spent $2.9 million. Their money, funny enough, has been spent portraying Cotton as a puppet of the people buying ads for him.

Arkansas is a relatively cheap state, and a lot of money has been spent to weaken Pryor. Despite the spin, Republicans see a victory here more easily than they see an upset in Michigan or Iowa or Colorado. But Pryor isn't losing. He's stayed bouyant in a red state. Four years ago, under what seemed to be similar circumstances (a two-termer seeking re-election against a challenger the House), Sen. Blanche Lincoln never, ever pulled her head above water. At this point in that cycle, she was 17 points down.