Two-term Arkansas Democrat Sen. Mark Pryor is considered the most vulnerable incumbent facing re-election in 2014, according to Roll Call.
Pryor, who is the son of David Pryor, a former governor and senator, has faced criticism for his support of Obamacare.
His likely opponent, freshman Republican Rep. Tom Cotton, has the support of both establishment and tea party Republicans in the state. Cotton's background includes service in the U.S. Army and a Harvard law degree.
Republicans are confident that he is the strongest challenger they could put up against the entrenched incumbent.
Pryor has a larger campaign war chest.
Democrats have tried to define Cotton as inexperienced and reckless, according to Roll Call.
Veteran Republican strategist Justin Brasell says that the Pryor campaign is engaging in character assassination, claiming that because Cotton has not spent the past eleven years in Washington, he is unfit for office.
"There's nothing positive for Pryor to point to," says Brasell.
"Arkansas is still a state that loves the Pryor family, and although some of the polling numbers might not reflect that, you're going to see his dad and some of the old guard that the state respects come out in large numbers and campaign aggressively for Pryor," said Republican strategist Sarah Huckabee Sanders.
The most recent poll on the race from the University of Arkansas, Fayetteville,
has Cotton up by one point on the incumbent.
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• Cotton Announces Bid for US Senate Seat in Ark.
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