A new ad released by Missouri Democrat Jason Kander shows the senatorial candidate piecing together a firearm and then challenging Sen. Roy Blunt (R-Mo.) to do the same. (Jason Kander)

Politicians have long liked to hold guns in campaign spots. They really like to fire them. Now, a candidate has introduced a new caliber of gun ad.

Democrat Jason Kander, who is challenging Sen. Roy Blunt (R-Mo.) for his seat, appears in an ad blindfolded and standing at a wooden table in a darkly lit warehouse. As he begins to speak, Kander starts piecing together a rifle. The metallic clank of each part falling into place accentuates his argument, and the beginning of the ad establishes his credentials as someone who knows how to use guns, and respects them, too. But despite his proclaiming of support for the Second Amendment, it's not an ad that's likely to make the National Rifle Association happy.

"I also believe in background checks, so that terrorists can't get their hands on one of these," Kander pivots.

Second Amendment advocates argue that background checks would limit a constitutionally guaranteed right, while background-check advocates say it's a simple matter of keeping weapons out of the hands of dangerous individuals.

Recent efforts at passing background-check legislation haven't gone very far in Congress. But the American public apparently isn't as split as the legislature; The Post reported last fall that about 85 percent of gun owners support universal background checks for purchasers.

Kander actually has a chance to take Blunt's seat; despite its GOP lean at the federal level, Missouri is ranked the 10th most likely to flip parties in The Fix's most recent Senate rankings, in part because Democrats consider Kander, a 35-year-old secretary of state and Afghanistan war veteran, a strong recruit.

If his newest ad resonates with voters, Kander will be that much closer.