Missourians for Kander/YouTube Army veteran Jason Kander is running for the US Senate to unseat Sen. Roy Blunt (R-Mo.), and he just dropped an incredibly effective ad pushing back on criticism of his gun rights positions.

He assembles an AR-15 blindfolded while simultaneously talking about his time serving as an intelligence officer in Afghanistan. "I approve this message, because I would like to see Sen. Blunt do this," he says, holding up the finished rifle, in what is the political equivalent of a mic drop.

Last week, the National Rifle Association released an ad that criticized "liberal Jason Kander" for a 2009 vote against the defensive use of guns. The spot criticized the Democrat as being weak on Second Amendment rights.

In response, Kander is seen blindfolded in a new ad released Wednesday, pushing back on that view.

"Sen. Blunt has been attacking me on guns. In Afghanistan, I volunteered to be an extra gun in a convoy of unarmored SUVs," Kander says. "And in the state legislature, I supported Second Amendment rights. I also believe in background checks so that terrorists can’t get their hands on one of these."

Brandon Friedman, a former Army officer and CEO of public relations firm McPherson Square Group, told Business Insider the spot was "a masterpiece."

Still, Kander has an uphill battle in the race. His opponent Roy Blunt scored the endorsement of the influential NRA in April, and he currently leads the challenger by three points, according to the RealClearPolitics average of Missouri's US senate race.

Watch the ad below: