SOUTH DAKOTA: Republicans view South Dakota as a key potential pick-up, especially if Johnson retires. Johnson has made huge strides in recovering from a debilitating 2006 brain hemorrhage, but the state has trended sharply Republican in the past six years. Former two-term Gov. Mike Rounds began campaigning for the GOP Senate nomination shortly after the 2012 election, but it's not clear if Rounds, vulnerable to attack from spending hawks on his right, will face a primary challenge. If Johnson retires, former Rep. Stephanie Herseth Sandlin and Johnson's son, Brendan Johnson, the state's U.S. attorney, are potential prospects.
LOUISIANA: Democrat Mary Landrieu is again a prime target for Republicans as she seeks a fourth term. Republicans have yet to identify a challenger and Landrieu, the daughter of one of the state's most durable political families, has $2.5 million in her campaign account. Two Republican congressmen, Charles Boustany and Steve Scalise, have taken their names out of consideration while two House colleagues, physicians John Fleming and Bill Cassidy, are mulling bids, along with Lt. Gov. Jay Dardenne, a favorite of moderates. Tea party conservatives are pushing former Rep. Jeff Landry.
Republicans view West Virginia Rep. Shelley Moore Capito as a strong candidate to capture the seat of retiring Rockefeller. In North Carolina, Democrats are defending Sen. Kay Hagan in a state narrowly lost by Obama. And Alaska could be pivotal, with Sen. Mark Begich, a Democrat, potentially facing a challenge from Republican Lt. Gov. Mead Treadwell.
Beaumont reported from Des Moines, Iowa. Associated Press writer Bill Barrow in Atlanta contributed to this report.
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