Sen. Ben Nelson (D-Neb.) is getting some help at home: Democratic-affiliated political action committee Patriot Majority is running a television ad defending his fiscal record.

"Ben's fighting to tear up Washington's credit card while protecting senior citizens," says the ad's narrator. "No radical changes to Medicare or Social Security. No benefit cuts. No premium increases. Because Ben Nelson believes in responsible budget cuts that protect Nebraska's seniors."

This is the third state Patriot Majority has aired ads in: Their first two were to defend Sens. Jon Tester (Mont.) and Claire McCaskill (Mo.), two other Democrats from Republican-leaning states. All three are top GOP targets this year, and all three have recently faced attack ads from the Republican-affiliated outside group Crossroads GPS.

Nelson hails from by far the most Republican state of any Democratic senator up for reelection this year.