In this Feb. 27, 2015, file photo, Sen. Rand Paul (R-Ky.) speaks during the Conservative Political Action Conference (CPAC) in National Harbor, Md. (AP Photo/Carolyn Kaster, File)

Some sing for their supper. Others sing for “liberty.”

So if you happen to find yourself in Arlington on Tuesday night itching to exercise your vocal cords, expect to be inundated with “Stand With Rand” T-shirts, buttons and solicitations.

Sen. Rand Paul’s official presidential announcement conveniently coincides with the night D.C.-area “liberty activists” meet weekly to sing karaoke at an Irish pub in the Clarendon neighborhood, a haven for 20-something Hill staffers.

As it has for political campaigns before, the group is converting its booze-infused sing-along into a grass-roots fundraising opportunity for young people — one of Paul’s key demos. And the “Liberty Karaoke” event has spread well beyond the Washington beltway.

[Rand Paul seems to stray from libertarian roots as he courts GOP base]

When more than 200 people RSVPed to sing for Paul at O’Sullivan’s Irish Pub in Arlington, the group decided to take the celebration national.

“It sort of snowballed,” Matt Hurtt, the event’s organizer, told the Loop. Most of the copycat events have sprung up organically, with more than 50 karaoke parties planned around the country to cheer Paul’s run for the presidency. A full list is here.

Hurtt typically asks for a $35 entrance fee if the night is doubling as a fundraiser, but the event celebrating Paul is free, though he’s hoping people give $10 to $30 toward Paul’s presidential campaign.

There’s no official liberty song list, though Hurtt’s personal favorite is Bob Dylan’s “Subterranean Homesick Blues.” He often changes the lyrics in one stanza to: “The phone’s wiretapped anyway, Maggie says that many say/ They must bust in early May, orders from the NSA.

The parties are intended to dispel the stereotype that political fundraisers are for “stuffy old people” at hundreds of dollars a pop, he said.

Hurtt started the political karaoke nights in 2013, and benefactors Reps. Justin Amash (R-Mich.) and Thomas Massie (R-Ky.) have even made star appearances at the Arlington bar, though neither sang.

No “celebrity” guests are expected in Arlington for the Paul party, but Hurtt said there might just be a “very special guest at the Manchester, N.H. event.”

He wouldn’t confirm who, but he did say he’d been trying to get Paul to come to karaoke in Arlington for a year.

And he added, “I wish I could be in Manchester.”

Paul has been known to spin some virtual records on Twitter, sometimes with the hashtag #DJRandPaul. The Paul playlist has included such throwbacks as Coolio’s “Gangsta’s Paradise” and Chumbawamba’s “Tubthumping.” And once he dedicated Bon Jovi’s “Living on a Prayer” to Sen. Cory Booker (D-N.J.), the other half of his Senate bromance.

Hope Murphy’s Taproom in Manchester have those tunes on its karaoke list. Just in case.