A look at key House races so far:

Republican Seats:

— Arizona 1st Congressional District: First-term GOP Rep. Rick Renzi (search), who won narrowly in 2002, is a top Democratic target. Democrats pin their hopes on Paul Babbitt, the brother of a former governor and himself a former mayor.

—New Mexico 1st Congressional District: Republican Rep. Heather Wilson (search) is a perennial Democratic target in a district that Al Gore carried in 2000. She won a 10-point victory in 2002 against Democrat Richard Romero, who seeks a rematch this year.

— South Dakota At Large: GOP Rep. Bill Janklow (search) resigned after being convicted on a manslaughter charge stemming from a traffic accident, and a June 1 special election is scheduled. Democrat Stephanie Herseth, who lost to Janklow in 2002, is running again. The Republican contender is Larry Diedrich, a farmer and former state legislator. The GOP campaign committee began running ads earlier this month. Herseth is also airing commercials.

— Georgia 12th Congressional District: Freshman Rep. Max Burns (search) is a top Democratic target, even though George W. Bush won the district in 2000. Democrats have a primary to pick a challenger.

Democratic Seats

— Utah 2nd Congressional District: Democratic Rep. Jim Matheson (search) won by 1,600 votes two years ago in a district that gave Bush 67 percent of the vote in 2000, his best showing outside Texas. Republican John Swallow is trying for a rematch, but must survive a primary first.

— Kentucky 4th Congressional District: Conservative Democratic Rep. Ken Lucas (search) is retiring, and Republicans count this as among their best chances to gain a seat outside Texas. Nick Clooney, father of actor George Clooney, is the Democratic candidate. Geoff Davis, who lost to Lucas two years ago, is running again.

— Indiana 9th Congressional District: A rematch pitting Democratic Rep. Baron Hill (search) against Republican Mike Sodrel. Hill won 51-46 last time, but Bush carried the district, 56-42, four years ago. Hill voted against major Medicare legislation, one of few Democrats in potentially competitive districts to do so.

— Pennsylvania 17th Congressional District: Democratic Rep. Tim Holden (search) won a close election in a newly drawn Harrisburg-area district in 2002. Republicans have a multi-candidate primary in late April to choose an opponent.

Incumbent vs. Incumbent

— Texas 19th Congressional District: Veteran Democratic Rep. Charles Stenholm (search) running against first-term Republican Rep. Randy Neugebauer in one of the redrawn districts the GOP set up in hopes of gaining several Texas seats.

— Texas 32nd Congressional District: GOP Rep. Pete Sessions (search) vs. Democratic Rep. Martin Frost. Frost is in his 13th term; Sessions in his 4th.