Five years ago, Mr. Pryor coasted to a second term, but it was a different world. In 2008, Congress had dozens of conservative Democrats; the Tea Party had not yet made a mark on the GOP; and Arkansas remained a Democratic Party bastion, a holdout against the GOP tide that swept the South over the last half century.
Now, Mr. Pryor, son of one of Arkansas' most popular political figures, is the state's remaining Democrat in Congress and one of the last of Washington's "Blue Dogs," as the dwindling ranks of conservative Democrats are known. The state still has a Democratic governor, but since Mr. Obama was first elected president, Arkansas' state legislature and U.S. House delegation have flipped from blue to red.
Porter Briggs, a Little Rock businessman and lifelong Democrat, had always supported Mr. Pryor and Mr. Pryor's father, David Pryor, a former senator and governor. But disappointed in Mr. Pryor's support of the health-care law, Mr. Briggs said he let the senator know he would back his likely 2014 opponent, Republican Rep. Tom Cotton. The Arkansas Poll in October found voters evenly split between the two men.