It's October, but Republicans are already retreating in N.C.

With one month until Election Day, some big GOP spenders are giving up on North Carolina and prioritizing other states. Why it matters: It's a sign that Republicans believe Michael Whatley can't win and that the seat will flip to Democrats, who need four pickups to regain control of the Senate.Driving the news: Several key Republican super PACs have canceled October ad campaigns in North Carolina as polls show Whatley several points behind former Democratic Gov. Roy Cooper.By the numbers: Last month, Republicans spent $53 million on North Carolina's Senate race, while Democrats spent $44 milli