Indiana Secretary of State Todd Rokita won a crowded Republican primary race Tuesday night to become the likely replacement for retiring Republican Rep. Steve Buyer.

Rokita's victory came as Republican Rep. Mark Souder won his party's nomination for a ninth term after a nasty campaign in northeastern Indiana's 3rd District and fellow GOP Rep. Dan Burton squeaked by in the 5th District.

The race for Buyer's seat became a three-month sprint among 13 candidates after he announced in late January that he would retire after 18 years in Congress because his wife had been diagnosed with an incurable autoimmune disease.

Rokita defeated state Sen. Brandt Hershman, who is Buyer's district director and was endorsed by the congressman. Rokita had better name recognition going into the campaign as the winner of two statewide campaigns for secretary of state.

The district, which stretches from the Lafayette area through the western and southern suburbs of Indianapolis, is heavily Republican. Buyer typically won with more than 60 percent of the vote.

The winner of the Democratic nomination Tuesday was Purdue University biology professor David Sanders, who lost badly to Buyer in 2004 and 2006.

Souder, an eight-term congressman, defeated car dealer Bob Thomas, who spent much of his own money on television commercials portraying Souder as a career politician who wasn't a true fiscal conservative. Souder countered by emphasizing his A-plus marks from the National Rifle Association and 100 percent rating from the National Right to Life Committee.

Souder will face Democrat Tom Hayhurst, a former Fort Wayne city councilman who gave Souder a stiff challenge in 2006, in November.

Burton faced several challengers as he sought the Republican nomination for a 15th term in the 5th District, which stretches from suburban Indianapolis north into several rural counties.

Democratic Rep. Baron Hill won his party's nomination in the 9th District, where former Republican Rep. Mike Sodrel was trailing in his bid to again take on Hill.

Sodrel and Hill have faced each other in each congressional election since 2002. Sodrel won the seat in 2004, but Hill recaptured it two years later and won the 2008 election with nearly 58 percent of the vote.

Democratic Rep. Andre Carson easily defeated three challengers in the 7th District, where he is seeking his second full term to the seat once held by his late grandmother, Julia Carson. The district covers most of Indianapolis and is heavily Democratic. Barack Obama won 71 percent of the district's vote in 2008.

Carson will face Butler University professor Marvin Scott, who won the Republican race Tuesday.

State Rep. Jackie Walorski of Elkhart won the Republican nomination to face Democratic Rep. Joe Donnelly, setting up a potentially bruising campaign for northern Indiana's 2nd District seat in November.

Republican Rep. Mike Pence will have a rematch this fall against the Democratic candidate he's easily beaten the past two elections. Barry Welsh, a United Methodist minister from Connersville, won the Democratic primary Tuesday.

Pence, the third-ranking Republican in the U.S. House, is seeking his sixth term from Indiana's 6th District. He defeated Welsh in 2008 with 64 percent of the vote.