Sen. Pat Toomey finally has a challenger in Tuesday’s GOP Senate primary. Sort of.

Pennsylvanians for Self-Protection made a statement Wednesday telling its members to write in “2A” for the 2nd Amendment instead of voting for Toomey, who is running unopposed.

The gun-rights group is calling the write-in campaign against the incumbent “a protest for Senator Pat Toomey’s strong support for gun control legislation.”

“Pat Toomey has consistently sided with the gun grabbers,” the group’s president, Dave Sager, said. “He wants to do something about mass shootings in this country, we all do, but making it harder for law-abiding people to protect themselves with legal firearms isn’t the way.”

In early 2013, PA’s junior Senator co-sponsored a bill with Democratic West Virginia Sen. Joe Manchin to increase background checks in the wake of the Sandy Hook shooting. Though the bill was ultimately voted down in the Senate, gun-rights advocates point to the measure as an assault on their constitutional right to own a firearm.

“We need to send him a message and remind him that the 2nd Amendment is a right,” Sager said.