The Battle of Michigan Avenue is finally over, and it was won by the protesters.

The lopsided fight between anti-war demonstrators and the brutish police force of Chicago’s Democratic mayor Richard Daley the night of Aug. 28, 1968, in the midst of the Democratic convention, was a debacle for the left.

The protests didn’t stop the Vietnam War or the presumptive Democratic nominee, Hubert Humphrey, the sitting vice president who was much too establishment for the radicals.

The event, broadcast on TV — indeed, unfolding right in front of the hotel where reporters were staying — rent the Democratic Party asunder and effectively threw away any chance of beating Richard Nixon that year.

The New Left subsequently fell apart, and splintered several times over, until a faction resorted to lunatic violence (a return to Chicago in 1969 for a “Days of Rage” rampage through the streets was the prelude to more serious criminality).

Beginning in 1968, the Republicans won five of six presidential elections, and the man who put a stop to the run, Bill Clinton, was a Southern moderate who did everything he reasonably could to disassociate himself from any radicalism.

It’s hard to think of a direct action that more directly backfired than the Chicago protests. But the passage of several decades tends to alter judgments. So it is that, 50 years later, the Spirit of 1968 is in the ascendancy on the left and in the Democratic Party, which is moving toward a more open embrace of democratic socialism than perhaps could have been imagined by the protesters during those fevered summer nights in 1968.

Chicago was a war within the Democratic Party; there’s a reason the protesters didn’t show up at the Republican convention in Miami earlier that summer. Mayor Daley, and especially his cops, hated the demonstrators and showed it with the appallingly free use of their billy clubs. Now, much of the Democratic Party — certainly its rising figures — wants to cater to and capture the energy of the activists of the left rather than resist them.

There is still an establishment of the Democratic Party. The center of gravity has shifted, though, as labor institutions that once were culturally conservative and staunchly anti-communist have faded in significance, and true machine politicians like Mayor Daley have all but disappeared. This doesn’t mean that antifa — a fringe comparable to the Students for a Democratic Society in the late 1960s — is about to take over the party, but there’s very little check on its leftward movement, accelerated every day by the reaction against Donald Trump.

The radical critique of America emanating from the streets in 1968, as fundamentally racist, oppressive and corrupt, has more traction in the Democratic mainstream than ever before. Democrats like Elizabeth Warren and Andrew Cuomo, considering running for president in 2020, have to embrace it.

The obsessions of the New Left with race and gender, which came to define life on college campuses in the decades after the ferment of the late 1960s, have now been fully absorbed into Democratic thinking and argot.

The Democratic superdelegates, who arose in the 1980s and were a last vestige of direct establishment control over the party’s nomination (Hubert Humphrey didn’t have to win any primaries at all to get the nod in 1968), have just been sidelined.

The primary victory of Alexandria Ocasio-Cortez, a 28-year-old democratic socialist, over Rep. Joe Crowley, a 19-year incumbent and Irish-American pol who is a recognizable figure from William Daley’s party, crystallized the change that is afoot.

In 1968, the Democratic convention hall was fortified against the radicals by a steel fence topped with barbed wire, and guarded by thousands of cops and National Guardsmen. In 2020, presumably no such exertions will be necessary. The left will own the place lock, stock and barrel — because the protesters who got tear-gassed, beaten and bloodied on Michigan Avenue that notorious August night, in the fullness of time, prevailed.

Rich Lowry can be reached via e-mail: comments.lowry@nationalreview.com.