Agriculture Secretary Tom Vilsack reportedly predicted that Iowa would see a "holy war" if his wife runs for Congress, fueling speculation that she'll launch a high-drama challenge against conservative Rep. Steve King.

Christie Vilsack has been testing the waters for a potential House run and this week went live with her "Christie Vilsack for Iowa" website. The launch got a boost from the buzz created by her husband, a former Iowa governor, earlier in the week.

Tom Vilsack told a group of state senators Monday that "it will be a holy war" if his wife runs, the Des Moines Register reported. His wife's website then confirmed she was considering running in Iowa's 4th Congressional District -- the district that King, who represents the 5th District, is expected to run in following redistricting.

Such a face-off would pit a well-known Iowa name against one of its firebrand conservative voices in Congress. The possibility of a King challenge drew a quick retort from the conservative Club for Growth, which took exception at Tom Vilsack's remark.

"Before Christie Vilsack has her husband issue a fatwah against Steve King, she should know that Steve King has an excellent record in Congress on the issues that the Club for Growth cares about," Club for Growth President Chris Chocola said in a written statement.

Vilsack's website said she would "spend the next several weeks" talking with residents as she decides whether to run.