Sen. John McCain (R-Ariz.) today gave his endorsement to Tom Cotton, who is running for the GOP nomination in Arkansas’ 4th district. Cotton, an Army reservist with an impressive biography and a Harvard Law School degree, may get a boost from the endorsement in his competitive primary with 2010 GOP nominee Beth Anne Rankin.

“Tom Cotton volunteered to fight for our freedom in Iraq and Afghanistan when he could have continued a promising legal career,”  McCain said in a statement. “We badly need this kind of courage and selfless service in Congress — particularly to address our economic challenges. I’m asking the voters of the Fourth District to send Tom to Congress so he can join the fight for freedom there.”

In an interview with Roll Call in December, Cotton said he hoped to bring some of his military values to the Congress if he were elected.

“I think the Congress would probably be a little bit more respected if it had some of the values of the Army: things like accountability and honor and integrity,” he said.

The 4th district became an open seat after Rep. Mike Ross (D) announced his retirement to ponder a bid for governor in the Razorback State in 2014. Roll Call rates the race as Likely Republican.

The primary is May 22, with a possible runoff June 12.