Idaho House challenger Bryan Smith (R) released a new television ad Wednesday defending his career as a trial lawyer after a series of attacks.

The ad, titled “Guardian Angel,” features former client Shelli Long Kendrick praising Smith for suing her insurance company after it tried to avoid covering her cancer diagnosis when she was 13.

“Having help in any way ... it just changes your life. And I really just have to say thanks to him,” Kendrick says.

The story had previously been featured on Smith's website; this is the first time it has been made into a television ad.

Smith, who is backed by Tea Party-aligned groups including the Club for Growth and FreedomWorks, is attempting to unseat 2nd District incumbent Mike SimpsonMIchael (Mike) Keith SimpsonHouse panel votes to boost funding for Energy Dept., Army Corps Live coverage: Pruitt faces grilling in House hearings Green Party puts Dem seat at risk in Montana MORE (R), who enjoys strong backing from the U.S. Chamber of Commerce. The campaign has become a microcosm of a wider battle between establishment and Tea Party components of the Republican Party.

The Chamber of Commerce has launched repeated attacks on Smith’s career as a trial lawyer, with a February ad by the group saying Smith “stood in the way” of an Idaho effort to end “junk lawsuits.” In addition, an ad premiering Wednesday featuring Mitt Romney credits Simpson with working to “stop junk lawsuits” in a likely allusion to Smith’s career.