B-Real and Tom Morello from Prophets of Rage perform at EagleBank Arena in Fairfax, Va., on Aug. 19. (Kyle Gustafson/For The Washington Post)

There are so many reasons to get the band back together. Ego replenishment. Legacy maintenance. Good old American cash-sucking. But for Prophets of Rage — a hybridized Rage Against the Machine reunion that includes Chuck D of Public Enemy and B-Real of Cypress Hill — the band seems to be responding to some kind of Bat-Signal.

Upon announcing the group’s formation, the Prophets’ website declared, “We can no longer stand on the sidelines of history. Dangerous times demand dangerous songs.” In other words, the election cycle has gone totally septic, and these guys are sitting on some of the greatest protest music ever recorded. Duty calls.

That’s how they’re framing it, anyway. When the band launched its “Make America Rage Again” tour Friday night at Fairfax’s EagleBank Arena, one particular cluster of lyrics written by original Rage Against the Machine frontman Zack de la Rocha almost made this dizzy nostalgia trip feel like a new beginning: “It has to start somewhere. It has to start sometime. What better place than here? What better time than now?”

The big “it” in that song — 1999’s “Guerrilla Radio” — used to mean “the revolution” (I think.) What does it mean today? That’s even harder to say, especially for the Prophets, who spoke, between songs, exclusively in blurry platitudes of empowerment. If protest music implicitly urges the listener to ask questions, this gig generated plenty: Can we fight today’s war with yesterday’s weapons? Can nostalgia help illuminate a radical path forward? Was this concert designed to raise consciousness or simply to help people blow off steam? And is one more important than the other?

Also: Are these songs still dangerous? Were they ever?

B-Real and Tom Morello from Prophets of Rage perform in Virginia on Aug. 19. (Kyle Gustafson/For The Washington Post)

Here’s what we do know. Public Enemy’s first four albums stand as pop’s greatest artifacts of radical vision. As collated bundles of protest music, they remain the standard to strive for. Cypress Hill’s cloudy worldview wasn’t always overtly political, but all rap music arguably qualifies as an expression of resistance, even today. As for Rage Against the Machine, they wrote undeniably intoxicating rock anthems throughout the 1990s but were rarely taken as seriously as they took themselves. The band’s lyrics could feel vague, slogan-slick, scolding and humorless. Stylistically, they paved the sonic highway for a generation of less imaginative nu-metal bands that eventually chased their own platinum tails into the end times of mainstream rock.

If you first encountered the music of Rage Against the Machine during, say, puberty, you might have taken it very seriously. Suddenly, there were these guys talking about the Weathermen, the Zapatistas and Leonard Peltier, and they were doing it over riffs that refused to stop bouncing up and down on your pleasure center. Who else on MTV would dare? The band quickly became famous for a defiant refrain — “F--- you, I won’t do what you tell me!” — a line that simultaneously spoke to your adolescent suspicion of capitalism and your refusal to clean your room. Genius. Really.

“Anger is a gift.” That’s another de la Rocha aphorism from Rage’s 1992 debut album. But the band’s greatest gift was its strangely ecstatic skepticism, a form of heightened engagement merely posing as surly disengagement. Like so much great music, this stuff could help teach you how to live.

But if Rage Against the Machine truly enlightened you, it quickly became impossible to ignore the band’s highly compromised position. Here was a cadre of radical lefties spreading their gospel through the very corporate media channels they were encouraging their flock to dismantle. Oddly, this is what made the group singular. Rage Against the Machine was a band that could best measure its success by how many fans it lost.

For the faithful who convened Friday night in Virginia, the Prophets’ fuzzy political agenda was supported by an absolutely bulletproof sound. Guitarist Tom Morello, bassist Tim Commerford and drummer Brad Wilk peeled into 1992’s “Bombtrack” with unprecedented control, and the trio spent the rest of the night happily proving that they’ve written some of the greatest rock riffs of all time.

The hallmark boom of Chuck D’s voice added a new richness to the detonative force of the Rage Against the Machine songbook, even if he struggled to fall into the pocket from time to time. He’s clearly accustomed to dictating the swing of a song with his voice alone. Here, he was a guest.

That felt particularly bothersome during an awkward mash-up of Public Enemy’s indelible “Fight the Power” with the Beastie Boys’ “No Sleep Till Brooklyn,” but it felt even more glaring between songs. Compared with the handful of information-dense Public Enemy cuts that managed to pop up in the set list, Chuck D’s stage banter felt paltry and almost pointless. “Stay woke,” he shouted. “Pay attention.” “Take the power back.”

Morello spoke only once, letting fans know that a portion of the night’s profits would go to local homeless charities and urging them to “fight for the world you really want to live in.” But whatever political argument this collective was trying to make, it collapsed when B-Real encouraged fans to write Prophets of Rage on their election ballots come November. Maybe this was a tossed-off remark, but nothing should be tossed off on a tour as high-stakes as this one aspires to be. Instead of cultivating a heightened engagement, the Prophets seemed to be tapping into a dim sense of disillusionment — the same vibe that chokes the air at Donald Trump rallies.

Still, if you were interested in more than moshing through your memories, this show presented an opportunity to reconnect, in a very basic way, with your idealism. Maybe you failed to apply that idealism to your reality the first time around. Maybe the resurgence of this music is a cosmic nudge to try again. Maybe that’s a charitable way to think about it. But, you know, what better place than here? What better time than now?