The Democratic favorite is Michelle Nunn, the daughter for former U.S. Sen. Sam Nunn. Democrats are confident that she can pull in just enough Mitt Romney voters — rural and small-town whites fond of her father, and suburban white women in metropolitan Atlanta — for an upset.
—In Kentucky, McConnell finds himself criticized from the left and right. Wealthy businessman Matt Bevin may be a long shot in the Republican primary, but he's got enough organization and money to grab attention as he brands McConnell a capitulator to Obama.
Democrats back Secretary of State Alison Lundergan Grimes, a party financier's daughter who has gotten campaign advice and help from former President Bill Clinton. Like Nunn in Georgia, Grimes wants to win big among women. Like Bevin, she is going after McConnell as part of the problem in Washington, but she also says McConnell cares more about his national party post than about Kentucky.
McConnell has plenty of money to respond. He'd already spent $10 million by the end of 2013.
—In Louisiana, Landrieu is seeking a fourth term never having topped 52.1 percent of the vote. She won twice in Democratic presidential years. She won in the 2002, a midterm year, by running as a centrist who could work with a Republican White House. This time, she has to run with Obama's negatives — a 40 percent approval rating in Louisiana, according to Gallup — without having him at the top of the ticket to excite Democrats, particularly black voters.
U.S. Rep. Bill Cassidy has the backing of national Republican leaders and donors. But he once contributed to Landrieu and, as a state senator, he pushed a proposal similar to Obama's health insurance exchanges. At least two other Republicans will be on the all-party primary ballot, probably ensuring that Cassidy's best shot is a December runoff.