The changing political environment could be helping Sen. Richard Burr (R-N.C.) avoid a serious challenge in 2010.

Public Policy Polling, the Democratic-leaning firm based in North Carolina, just put out new numbers on Burr that show him leading a generic Democrat 45-34. Four months ago, Burr trailed that generic Democrat 41-38.

Burr has also extended his lead over all of his potential Democratic opponents to double-digits, including leading Rep. Bob Etheridge (D-N.C.) 44-33 and Secretary of State Elaine Marshall 44-32. Marshall is in the race; Etheridge is weighing it.

Burr's favorable numbers remain largely unchanged, so it doesn't appear to be anything that he's doing. But perhaps more than any other state that voted for President Obama last year, North Carolina is experiencing buyer's remorse.

Obama's approval rating in the state has sunk from around 60 percent early this year to the mid-40s, with more North Carolinians disapproving of him than approving of him.

Burr, who looked like one of the most vulnerable GOP incumbents at the beginning of the year, will likely remain a target because of his favorability numbers, but he's looking to be in better and better shape, and that could scare away someone like Etheridge.