A super PAC supporting members of Congress targeted by the tea party is launching its second TV ad in Idaho on Thursday.  

Defending Main Street PAC, led by former Rep. Steven C. LaTourette, R-Ohio, has now spent around $500,000 to help Rep. Mike Simpson, R-Idaho, who is facing a significant primary challenge.  

In the group’s latest ad, a narrator labels Simpson a “conservative fighting for Idaho” and says he “supports tax cuts that lower energy costs and reduce our dependence on oil from hostile nations, while protecting and creating jobs at the Idaho National Labratory.” www.youtube.com/watch?v=t1zSE0YmP58  

The race is a top target for outside groups like the Club for Growth, which is supporting attorney Bryan Smith. The National Rifle Association reported a $166,000 TV ad buy to the Federal Election Commission on Wednesday in support of Simpson.  

The primary is May 20.  

The winner will be heavily favored against former Rep. Richard Stallings, D-Idaho. The race is rated Safe Republican by Rothenberg Political Report/Roll Call.