(Reuters) - Departures and primary losses for 28 Republicans in the U.S. House of Representatives have created opportunities for a new wave of conservative and Tea Party-backed candidates. Here are some of the most notable departures and the candidates vying to replace them:
ALABAMA - Spencer Bachus, 66, retiring. The Republican nominee to replace him is Gary Palmer, a fund raiser for a conservative think tank in Alabama who is backed by the anti-tax group Club for Growth.
CALIFORNIA - Howard "Buck" McKeon, 75, chairman of the House Armed Services Committee, retiring. Two Republicans, state Senator Steve Knight and former state Senator Tony Strickland, will face off in the November election.
-- John Campbell, 58, retiring. The Republican nominee to replace him is state Senator Mimi Walters.
-- Gary Miller, 65, retiring. The Republican nominee is Iraq war veteran Paul Chabot. This is one of the few races in which Democrats could win a Republican seat.
GEORGIA - Jack Kingston, defeated in a U.S. Senate runoff election. The Republican nominee to replace him in the House is state Senator Earl "Buddy" Carter, owner of a pharmaceutical firm.
-- Phil Gingrey, 70, lost in the Senate primary. The Republican nominee is state Senator Barry Loudermilk, backed by the Club for Growth.
-- Paul Broun, 67, lost in the Senate primary. The Republican nominee is Baptist minister and conservative radio talk-show host Jody Hice, who has said First Amendment religious freedoms should not apply to Islam.
IOWA - Tom Latham, 65, retiring. The Republican nominee is David Young, a former chief of staff to Senator Charles Grassley.
LOUISIANA - Bill Cassidy, 56, running for U.S. Senate. Six candidates are vying in Louisiana's "jungle primary" election on Nov. 4. If none wins more than 50 percent of the vote, the top two vote getters face off in a Dec. 6 runoff election
MICHIGAN - Mike Rogers, 50, retiring. The Republican nominee is former state Senate majority leader Mike Bishop.
-- Dave Camp, 60, retiring. The Republican nominee is state Senator John Moolenaar, endorsed by some Tea Party groups.
-- Kerry Bentivolio, 62, defeated in the primary by Michigan's top foreclosure attorney, David Trott, who was endorsed by former Republican presidential candidate Mitt Romney.
NEW JERSEY - John Runyan, 40, retiring. The Republican nominee is former insurance company executive Tom MacArthur in a race where Democrats see a possible opportunity.
NORTH CAROLINA - Howard Coble, 82, retiring. The Republican nominee is Baptist preacher Mark Walker, a newcomer to politics.
OKLAHOMA - James Lankford, 46, a member of the House Republican leadership, running for the Senate. The Aug. 26 Republican runoff primary pits retired Army officer and former state Senator Steve Russell against Oklahoma Corporation Commissioner Patrice Douglas.
PENNSYLVANIA - Jim Gerlach, 59, retiring. The Republican nominee is Chester County Commissioner Ryan Costello, who was unopposed in the primary.
Texas - Ralph Hall, 91, defeated in a primary by Tea Party-backed John Ratcliffe, a former U.S. attorney also endorsed by the Club for Growth.
-- Steve Stockman, 57, lost in a U.S. Senate primary. The Republican nominee is physician Brian Babin.
WISCONSIN - Tom Petri, 73, retiring. The likely Republican nominee is state Senator Glenn Grothman, with state Senator Joe Leibham trailing by 214 votes.
VIRGINIA - Eric Cantor, 51, defeated in a primary by Tea Party-backed economics professor Dave Brat.
-- Frank Wolf, 75, retiring. The Republican nominee is Virginia state legislator Barbara Comstock, considered a Republican establishment candidate.
WASHINGTON - Richard "Doc" Hastings, 73, retiring. Tea Party favorite Clint Didier, a former Washington Redskins tight end, will face off against fellow Republican Dan Newhouse, a farmer, in the general election after winning the most votes in the state's "top-two" primary system.
WEST VIRGINIA - Shelley Moore Capito, 60, running for Senate. The Republican nominee is Tea Party-backed Alex Mooney, former party chairman in neighboring Maryland.
(Reporting by David Lawder; Editing by Leslie Adler)