Attorney Bryan Smith went on the air with a new television ad calling his primary rival, Rep. Mike Simpson, R-Idaho, a “liberal.”  

Smith is challenging Simpson, an eight-term incumbent and top ally of Speaker John A. Boehner, for the 2nd District in one of the cycle’s top primary battles . Smith also boasts the backing of several conservative outside groups, including the Club for Growth and Senate Conservatives Fund .  

The spot features an edited clip of Simpson saying, “Let me tell you about earmarks. I’ve always been a supporter of earmarks.”  

www.youtube.com/watch?v=BepEb2Rq1pI  

The Smith campaign has reserved $25,000 in the Twin Falls and Idaho Falls media markets for the spot. While that’s a small figure, Idaho is a cheap place to buy airtime for radio and television.  

As a result, voters are likely to see much more advertising before the May 20 primary. Simpson went on the airwaves with his first spot in March.  

The race is rated Safe Republican by Rothenberg Political Report/Roll Call.