[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2010/images/04/20/art.stutzman.stutzman.jpg caption="Just two weeks after finishing a surprising second in Indiana's Republican Senate primary, state senator Marlin Stutzman is making another bid for office."](CNN) - Just two weeks after finishing a surprising second in Indiana's Republican Senate primary, state senator Marlin Stutzman is making another bid for office.

Stutzman announced Thursday that he would seek the House seat of fellow Republican Mark Souder, who is resigning following his admission of an extramarital affair.

"We must have strong, principled, accountable leadership in Washington that will stand strong for Hoosier values and represent 'We the People,"' said Stutzman, in formally announcing his candidacy.

Souder abruptly announced his resignation Tuesday, after acknowledging that he "sinned against God" by engaging in a relationship with a member of his staff. The 59-year-old married father of three, who just won a competitive primary, said he will leave office at the end of the week.

Souder, a social conservative, was first elected to Congress in 1994 and represents Indiana's third Congressional district, located in the northeast region of the state.

Stutzman is a farm owner in the district. He won the backing of many Tea Party activists and of conservative Sen. Jim DeMint of South Carolina in his bid for the GOP Senate nomination. He lost to former Sen. Dan Coats but came out ahead of former Rep. John Hostettler, who was much better known across Indiana.

Other GOP candidates may jump into the contest for the open seat. Party caucuses of committee members will choose the nominees in the race. No date has been scheduled for the special election.

Former Fort Wayne city councilman Tom Hayhurst is the Democratic nominee for November's general election. He could become his party's pick for the special election.

Follow Paul Steinhauser on Twitter: @psteinhausercnn