The Obama campaign has sent letters to radio stations in Ohio and Pennsylvania discouraging them from running ads by the National Rifle Association critical of Barack Obama. Ben Smith reports:

"This advertisement knowingly misleads your viewing audience about Senator Obama's position on the Second Amendment," says the letter from Obama general counsel Bob Bauer. "For the sake of both FCC licensing requirements and the public interest, your station should refuse to continue to air this advertisement."

Smith's Politico story also includes the NRA's response to critiques of its ads which, it claims, are only running in Pennsylvania at the moment.

UPDATE: Here is a PDF of the Obama campaign's letter.

This roundup at Instapundit suggests this letter could be part of a broader effort to squelch critical voices.