Dawn Ursula floats in as the Angel in Round House Theatre and Olney Theatre Center’s revival of “Angels in America Part I: Millennium Approaches.” (Danisha Crosby)

An angel does materialize, magisterially, in the closing moments of “Angels in America Part I: Millennium Approaches,” Tony Kushner’s epically engrossing, acidly funny masterwork. But demons prowl just as captivatingly in the confines of Round House Theatre, which, in a welcome collaboration with Olney Theatre Center, is giving Washington audiences their first big-stage immersion in the play in eons — and soon, will add its slightly unwieldier second half, “Part II: Perestroika.”

The devil in chief is a character whose name also crops up often these days in coverage of the 2016 election: Roy Cohn, the scabrous legal mudslinger, associate architect of McCarthyism and, as we’ve learned, late mentor to one Donald J. Trump. That Cohn, electrified here by Mitchell Hebert in a performance of equal parts venom and bile, should have been stamped forever by Kushner as the embodiment of a grasping and predatory age, speaks to the playwright’s prophetic gifts. For prophecy is an important element of “Angels,” and the acuteness of Kushner’s vision helps us to ­understand why this award-showered pair of plays remains vital and equal to the test of time.

Yes, things have changed in the quarter-century or so since ­“Angels in America” took its first bows, and thus some of its ­middle-of-the-tsunami energy has dissipated: AIDS, a ­plot-driving centerpiece of the works, is no longer (for most people) an automatic death sentence, and the advances (and scattered setbacks) in the cause of gay rights have the effect of muting some of plays’ characterizations of the marginalization of gay people.

Still, as a meditation on the America of Ronald Reagan — “Millennium” begins in 1985, during Reagan’s second term and the explosion of the AIDS epidemic — “Angels” is a potent living document. While it’s far from ideologically neutral, the tone is by some magnitude more lyrical and sardonic than, say, Larry Kramer’s marvelously seething AIDS play “The Normal Heart,” which wears as a badge of honor its passionate indictment of the Reagan administration’s derogation of responsibility in acknowledging and committing resources to the plague.

“Angels” explores something deeper than health policy: For all its impressive ruminating about ethics and politics, it’s really about love as a transcendent force — the one power quested for by every character in this sprawling American tapestry. And yet, too, the play speaks to current events with an almost eerie resonance. Listen to the conversation about race between Jewish, intellectually overconfident Louis (an excellent Jonathan Bock) and black, terminally exasperated Belize (the superb Jon Hudson Odom), and you’d swear the dialogue was composed only yesterday. Or consider the remarks by a Reagan Justice Department functionary (the protean Kimberly Gilbert), expounding on a Republican master plan to wipe out liberalism, and you’ll hear the groundwork being laid for the legislative gridlock overwhelming Washington today.

Kimberly Gilbert as Harper on James Kronzer’s Round House Theatre set for “Angels in America Part I: Millennium Approaches.” (Danisha Crosby)

Perhaps, though, given the rampant irrationality that seems to have convulsed our political culture, the most incisive prediction in “Millennium Approaches” comes from a homeless woman in the Bronx (Dawn Ursula), who declares while rummaging through her boxes and rags that “in the new century, I think we will all be insane.”

The play gives us touchstone figures whose lives seem to be barreling toward disaster. (Even the characters’ hallucinations bump messily onstage into one another.) One arc traces the assault of AIDS on the body of Prior Walter (Tom Story, in an endearingly droll portrayal) and the cowardly retreat from his life by his lover, Louis. Another follows the disintegrating marriage of a Mormon couple living in Brooklyn, Harper (Gilbert) and Joe (Thomas Keegan, in some of his best work to date). Joe is a closeted gay lawyer whom Cohn seeks to co-opt, and whose lack of interest in his wife has driven her around the pill-popping bend. The subplots coil around each other, carried along on a bountiful supply of vivid minor characters: Everyone in the cast of eight plays multiple roles.

Director Jason Loewith, Olney’s artistic head, leans confidently on Kushner’s cerebral comic impulses — we can forget sometimes that “Angels in America” is chocka­block in jokes and cheeky asides; the cultural references range from de Tocqueville’s “Democracy in America” to Broadway’s “La Cage aux Folles.” Loewith’s well-handled direction, especially in scenes involving Hebert’s reptilian Cohn or Bock’s bookwormish Louis, crackle with epigrammatic virtuosity. Sarah Marshall’s numerous turns here — as a rabbi; Joe’s mother from Salt Lake City, Hannah; and most delightfully, the ghost of Ethel Rosenberg — resound with all the acerbic wit one could wish for.

The director and his set designer, James Kronzer, present “Angels” in front of a flight of stairs and the giant windows of an imposing facade that suggest a setting both grand and grim. How projection designer Clint Allen and lighting designer York Kennedy transform that static frame into something that at various times shimmers colorfully or is disrupted by disturbing images proves a cool bonus. (There’s a nagging sense of a haunting hovering over the production.) Ivania Stack’s costumes and Joshua Horvath’s sound design are crisp and polished assets as well.

This secure mounting of one of the great theatrical projects of the latter half of the 20th century attests to the artistic vigor that Loewith and his Round House counterpart, Ryan Rilette, are bringing to their companies. The array of first-class Washington actors they’ve added to their “Angels” underscores the size of synchronized mutual aspirations. Rilette continues the collaboration with his direction of “Perestroika,” which starts performances at Round House on Sept. 25. Then the two plays run in rotating repertory in October.

Let’s have more of this, so that — to paraphrase Kushner — the great work continues.

Angels in America Part I: Millennium Approaches, by Tony Kushner. Directed by Jason Loewith. Set, James Kronzer; projections, Clint Allen; costumes, Ivania Stack; lighting, York Kennedy; sound, Joshua Horvath; fight choreography, Casey Kaleba; dramaturge, Gabrielle Hoyt; flying, D2 Flying Effects; dialects, Zach Campion; assistant direction, Philip Kershaw. About 3 hours, 10 minutes. Tickets, $30-$75. Through Oct. 30 at Round House Theatre, 4545 East-West Hwy., Bethesda. Visit roundhousetheatre.org or call ­240-644-1100.