In 2005, Rainville began consulting with members of the Republican and Democratic parties regarding a possible run for the U.S. House of Representatives or the U.S. Senate. She was courted by members of both parties and announced in the spring of 2006 that she would run for Vermont's U.S. House seat as a Republican, intending to base her campaign on government reform and ethics, homeland security, and a strong national defense. She won the Republican nomination with 71 percent of the primary vote, to 28 for Mark Shepard, a member of the Vermont Senate.