"He did well in the Senate race and certainly had a following," said Bob Schmuhl, a political analyst and University of Notre Dame professor.
But it could be a problem for Stutzman to run for another office so soon, said Dan Parker, chairman of the Indiana Democratic Party.
"It takes away from his ability to say he's not a career politician, which was his argument against Dan Coats," Parker said.
Throughout his time in Congress, Souder made his evangelical Christianity a centerpiece of his public persona, with strong stances on abortion and traditional marriage. As a lawmaker, Souder was best known for his work on drug enforcement issues and his opposition to online gambling.
Republicans hope the district's GOP tendencies will prevail in November. Souder was to have faced Democrat Tom Hayhurst, a former Fort Wayne city councilman who got 46 percent of the vote against Souder in 2006 — the toughest challenge since Souder was first elected in 1994.
"I'm not running for Congress to run against anyone, but I'm running because I think I can help change Washington and that will not change not matter who is in the race," Hayhurst said.