Majority PAC boosted vulnerable Sen. Ben Nelson (D-Neb.) with an ad buy in his home state this week.

The political action committee’s spot lauds Nelson’s work with veterans across the state, and it will run in four media markets for $72,000, according to a source with knowledge of the ad buy.

Three Republicans are running for the chance to challenge Nelson: state Attorney General Jon Bruning, state Treasurer Don Stenberg and state Sen. Deb Fischer.