Dividing lines

Pryor’s voting record earned him a career 19.8 American Conservative Union rating, while Cotton checks in at 92 percent. Cotton led Pryor by 3 percent in the Real Clear Politics polling average in early August.

In addition, Cotton’s southern Arkansas district is a swing area of the state where experts believe Democrats must over-perform to win. This may be a tall order for Pryor, who must run not only against the likable Cotton but also the unpopularity of Obama.

Pryor’s website argues that the senator “ignores partisan politics to do his very best for the people of Arkansas.”

“Instead of ‘politics as usual,’ Mark works for responsible, bipartisan solutions that secure the future of our nation for generations to come while keeping our commitments to our seniors and veterans,” his campaign states. “With Mark Pryor, ‘Arkansas Comes First.’”

Because Arkansas traditionally ranks near the bottom in per capita income, look for economics to be a hot issue for Cotton. Immigration policy also is likely to be a factor. Arkansas is only one state away from the border, and major employers such as Tyson are labor-intensive. However, Murphy from the NRSC advises voters to focus in on the one factor that likely will decide the race.

“The big issue is Obamacare and Barack Obama’s liberal agenda,” he said. “Only 37 percent of Arkansans voted for Obama in 2012, and nothing has changed since then. That is one big reason why Pryor has been trailing in most polls.”

David Ray, a spokesman for Cotton, agreed: “For the last six years, Sen. Pryor has carried the water for big labor, rubber-stamped President Obama’s health-care demands and taxed and regulated businesses to death. We can do better by electing Tom Cotton, who will work to lower taxes, rein in spending, and start over on true health-care reform.”