Congressman Andy Harris is turning 59, and D.C. activists want to make the most of his birthday celebration.

Harris has been in the crosshairs of advocates ever since the Maryland Republican successfully introduced an amendment to block the implementation of the city’s marijuana decriminalization law.

DCMJ—which crashed a town hall hosted by Harris last month—is returning to suburban Maryland this upcoming Tuesday to protest outside of the party and to register voters for the upcoming primary. “Celebrate our Overlord, PoopyMonkeyBaby’s Birthday,” a flyer for the event says. The nickname is a play on the Mountain Dew Super Bowl commercial featuring a “Puppy Monkey Baby.”

“The first time I heard that I thought, ‘Did they say poopy?'” says Adam Eidinger of DCMJ. “And then I thought, ‘Who is a poopy monkey baby? Oh, that’s Andy Harris.’ The Mountain Dew commercial targeted 20-somethings and that’s who we’re trying to target.” Already, he says at least 25 people have expressed interest.

When DCist spoke to Eidinger, he was at the United Nations, attending a meeting about drugs ahead of April’s special session on the world drug problem. He says he has been passing out liberty caps.

Harris reacted with less enthusiasm to the distinctive red hats last month, refusing Eidinger’s offer of one. Eidinger says that, after meeting Harris face-to-face at last month’s town hall, he has no hope that Harris’ positions on marijuana or statehood will change. “Now there’s nothing left to do but ruin the man’s reputation and run him out of office,” says Eidinger. “It’s time to take off the gloves.”

DCMJ has a multi-pronged plan for the protest. Some attendees will head to a nearby business district to register voters. “We’re trying to get people to switch from independent to Republican to vote in the primary,” says Eidinger.

One of Harris’ opponents in the primary is former Maryland House of Delegates member Michael Smigiel, who told DCist that Harris’ stance on marijuana “isn’t that different from King George’s…if you make yourself a symbol of fighting marijuana, you will be removed.” A poll commissioned by Smigiel’s campaign in January has him up 58 percent to Harris’ 29 percent in the primary.

Others will remain outside of Harris’ birthday party, which costs $59 to attend. “We probably won’t be allowed in, but that’s okay,” says Eidinger, who says the goal is to talk to Harris’ supporters as they enter and exit. While he pledges a polite showing, he adds that “there may be some heavy metal.”