Edward Gero plays Supreme Court Justice Antonin Scalia for the world premiere of "The Originalist" at at Arena Stage. (Arena Stage)

Is the bulldog conservative justice we see parading up and down the stage in “The Originalist” the Antonin Scalia? That’s a verdict for the Supreme Court justice’s intimates and close observers to render, though Edward Gero’s lively performance at Arena Stage makes an extremely compelling case.

He bellows. He bullies. He quips. He warbles opera (badly). He’s combustible and rigorous. He’s dark-haired and a little stout, with a lower lip protruding like he’s daring you to take a swing. If this is not Scalia to the last degree, in Gero’s exacting hands this is certainly a man in full.

He’s a monster in the eyes of his rivals and he knows it — relishes it, even — which is the launching point of John Strand’s daring new play at Arena. It takes chutzpah to cross-examine a figure like Scalia on the stage, and Strand doesn’t soft-pedal it. For about an hour and 45 minutes (without intermission), Scalia gets pushed on his legal theory of “originalism” — trying to stick to the words in the U.S. Constitution, not treating it as a “living document” that shifts with the times. He’s also challenged in no uncertain terms on legal opinions that at their worst rankle opponents as racist and homophobic.

The script particularly digs into the 2013 U.S. v. Windsor case that invalidated parts of the Defense of Marriage Act, a victory for the same-sex marriage movement that was decided 5-4 with a heated dissent from Scalia. But the bigger concern of “The Originalist” is the ugly way we do battle in the public arena, calling names and demeaning opponents in a discourse that has turned notoriously sour. (It was a surreal experience Thursday night to watch the tube an hour after this peacemaking show and see Jon Stewart ritually flaying his bête noire, Fox News.)

You can see why Strand would latch onto Scalia for this. The boxing idea is put front and center as Scalia takes on a new clerk and intellectual sparring partner named Cat (Kerry Warren) who is everything he is not: young, female, child of an African-born mother and . . . well, there’s a little more to her profile that shouldn’t be spoiled (though you can probably guess). From the moment she impulsively interrupts his speaking engagement at a law school, it’s plain that Cat is (gasp!) a liberal.

Gero as Supreme Court Justice Antonin Scalia. (C. Stanley Photography)

“Flaming,” she tells him.

The oddity of the play is that he is more believable than she is, at least in this premiere production. Warren’s performance is fierce and knowledgeable, but this Cat is so intense and so rudely in the conservative lion’s face that you keep expecting Scalia to get rid of her with a roar and a fast fatal swipe. You wonder if it’s possible for Warren and director Molly Smith to temper the characterization a little, to make Cat’s edges as round and full bodied as Scalia’s. (There is a subplot about her dying father, but it’s debatable which character this humanizes more.)

But then a key idea of Strand’s is to create an opponent as inflexible as we think this justice is, so Scalia and Cat meet on a kind of hotheaded odd-couple footing. She lectures him on humanity, he teaches her how to fire a rifle, and their disagreements — Cat’s especially — sometimes slide into unhearing self-righteous harangue. The young Cat has a right-wing rival in Brad, too, a Scalia sycophant played by a slightly smug Harlan Work, and while it’s no surprise that those two push each other’s buttons and end up in a literal food fight, it’s also one of the play’s least persuasive moments.

Even so, Arena’s glorious Kogod Cradle hasn’t felt this alive with new writing in a while. It’s a play that avidly interrogates our political practices. Smith and designer Misha Kachman have reconfigured the 200-seat theater with a deep thrust stage that puts the audience on three sides, a ripe environment for listening and judging. Strand’s ending may even send you to Google to read exactly what Scalia wrote in his Windsor dissent.

Ultimately, there’s Gero: Strand has given the longtime Shakespeare Theatre Company actor sumptuous layers with which to work, from impish entertainer to tragic figure. He lands the laughs, delivers the gravitas and at every turn makes you believe this tantalizing man knows and feels American law down to his very bones.

The Originalist

By John Strand. Directed by Molly Smith. Costumes, Joseph P. Salasovich; lights, Colin K. Bills; composer, Eric Shimelonis. About an hour and 45 minutes. Through April 26 at Arena Stage, 1101 Sixth St. SW. Tickets $55-$150, subject to change. Call 202-488-3300 or visit www.arenastage.org.