The National Republican Congressional Committee will drop $150,000 on ads supporting Jesse Kelly, the GOP nominee in the special election to replace former Rep. Gabrielle Giffords (D-Ariz.).
It's the NRCC's first independent expenditure of 2012, a GOP source said, signaling the emphasis Republicans have placed on winning back the competitive seat in southern Arizona.
Kelly edged out three Republican opponents to win the nomination in April. Democrat Ron Barber ran unopposed.
"It isn't surprising that Washington Republicans would come into our district in support of a candidate who shares their values in wanting to dismantle Medicare and who has said he wants to phase out Social Security," said Barber spokeswoman Jessica Schultz. "They know that Ron Barber will fight to protect Medicare and Social Security."
Barber served as Giffords's district director and was shot twice in the January 2011 shooting spree that also critically injured Giffords and led to her resignation from the House one year later.
Kelly, a veteran and Tea Party favorite, narrowly lost a challenge to Giffords in 2010.
The special election to finish Giffords's term is being conducted under current districting lines, which give Republicans an advantage. A separate, regular election for the full term starting in 2013 will be held in the fall under new lines that make the district slightly more favorable for Democrats.