Senate GOP Invests Money in Tight Indiana Race

Democratic candidate Joe Donnelly has stayed neck and neck with Republican Richard Mourdock since May.

Senate Republicans will jump into Indiana's pitched Senate battle this week, responding to a Democratic ad-buy with one of their own as they seek control of the Senate in November.

The National Republican Senate Committee will spend $650,000 on an ad that will run statewide on broadcast and cable for one week starting Tuesday. A Republican Party source tracking ad buys confirmed the new spot Sunday on condition of anonymity because it has not aired yet.

The NRSC buy tops Senate Democrats', who have spent $516,000 on a spot airing at the same time, and marks the committee's first foray on air in Indiana this cycle.