Rep. Joe Donnelly (D) is set to hit the airwaves Friday with his first general election television ad of the Indiana Senate race, a $250,000 statewide buy.

According to a copy of the spot obtained by Roll Call, the 30-second advertisement paints GOP nominee Richard Mourdock as an extremist and highlights Donnelly’s bipartisanship in Congress.

“To me, the highlight of politics, frankly, is to inflict my opinion on somebody else,” Mourdock, a state Treasurer, says in the on-camera MSNBC interview that is used in the spot. (View the full spot after the jump)

Democrats see the Indiana Senate races as increasingly competitive since Republicans nominated Mourdock over six-term Sen. Dick Lugar, who was known for reaching across the aisle.

What’s more, the Democratic Senatorial Campaign Committee wants to show it — by dipping into its own funds. A DSCC source notes that the committee transferred $250,000 to the Indiana Democratic Congressional Victory Committee to the run this spot.

The $250,000 buy will put the advertisement on cable and broadcast statewide for the next two weeks, according to a Democratic ad-buying source.

Democrats hope the spot will answer the massive recent statewide ad buy from Crossroads GPS. The conservative third-party group spent $620,000 on a two-week buy targeting the Senate race over two weeks, a Crossroads GPS spokesman confirmed.