BOISE, Idaho (AP) — A fiscally conservative anti-tax group is aiming to unseat U.S. Rep. Mike Simpson of Idaho in next May's Republican primary. The Club for Growth announced Wednesday it's supporting Simpson's GOP challenger Bryan Smith, an Idaho Falls lawyer.

Smith brands Simpson a big-spending politician, while Simpson is on Club for Growth's list of Republicans to jettison in 2014. Simpson has drawn the group's ire on a series of votes, including the federal government's 2008 bank bailout. The Washington, D.C.-based group has been active in Idaho GOP politics before.

It spent more than $1 million in 2006 to help elect Republican U.S. Rep. Bill Sali in Idaho's 1st Congressional District. Simpson, an eight-term Republican in Idaho's 2nd Congressional District, survived challenges in his 2010 and 2012 primaries from a libertarian-leaning rival.