If you want an illustration of the current Democratic dilemma on guns, look no further than the special congressional election in Pennsylvania’s 18th District, which will be decided on Tuesday.

Recent polls show Democrat Conor Lamb running neck and neck with his Republican opponent Rick Saccone. Democrats are looking at an improbable prospect: Lamb could win a deeply red district that Democrats were never even supposed to be competitive in. And part of the reason he might be doing so well is his pro-gun messaging.

Lamb’s first campaign ad featured footage of him shooting an AR-15 semiautomatic rifle at a gun range, with the narrator voiceover saying the candidate “still loves to shoot.”

Republicans have been trying furiously to attack Lamb on the gun issue, painting him as someone who will pursue aggressive gun control policies if elected to Congress. But he’s not giving them a lot of ammunition to work with. A US Marine Corps veteran, Lamb is on the record as not supporting additional gun control measures.