Aaron Sorkin’s ‘The Trial of the Chicago 7’ is an entertaining - and stirring - history lesson

At least two brilliant films have been made about the antiwar demonstrations and police riots that took place at the 1968 Democratic National Convention in Chicago. HaskellWexler’s “Medium Cool,” released in 1969, blended documentary footage with a fictional story to create a vividly immediate sense of the twitchy unease and ultimate anarchy that ensued during those August days. In 2007, the filmmaker BrettMorgen revisited the trial of several activists whowere accused of conspiracy and inciting a riot in his masterfully executed animated nonfiction film “Chicago 10.”

With “The Trial of the Chicago 7,” writer-director Aaron Sorkin delivers a more straightforward but no less stirring re-creation of an episode that can’t help but feel timely in an era when America is riven by polarization not seen since the 1960s. (Sorkin’s sevenrefer to the defendantswho were left after one of them, Black Panther Party co-founder Bobby Seale, was severed fromthe trial; Morgen also included the activists’ lawyers, William Kunstler and Leonard Weinglass.)

Briskly paced, bristling with Sorkin’s distinctive verbal fusillades, seamlessly blending conventional courtroom procedural with protest re-enactments and documentary footage (including Wexler’s), “The Trial of the Chicago 7” offers an absorbing primer in a chapter of American history that was both bizarre and ruefully meaningful. The fact that it’s also a showcase for some of the most dazzling performances on screen this year elevates it beyond mere history lesson and into something far more animated, exciting and viscerally entertaining.

Echoing Spike Lee’s “Da 5 Bloods” this summer, “The Trial of the Chicago 7” opens with a helpful refresher course on why 1968 was such a pivotal year:

With Lyndon Johnson having increased troops in Vietnam and casualties growing by the day, a loose coalition of groups - including the Students for a Democratic Society, the Yippies, theNational Mobilization Committee to End the War in Vietnam and others - descended on Chicago to protest the presumed Democratic nominee, Hubert Humphrey, who had supported Johnson’s escalation. Thankfully, Sorkin doesn’t dive right in to the bloody clashes between demonstrators and Chicago police that left hundreds seriously injured. Rather, he begins in the office of U.S. Attorney General JohnMitchell (John Doman) who, a year after the events, is determined to punish the subversives by way of a federal trial.

What transpired over the next five months was an almost surreal piece of long-playing political theater, as Yippies Abbie Hoffman and Jerry Rubin (Sacha BaronCohenand Jeremy Strong), SDS leaders Tom Hayden and Rennie Davis (Eddie Redmayne and Alex Sharp), veteran peace activist David Dellinger (John Carroll Lynch) and the now almost-forgotten Lee Weiner and John Froines (Noah Robbins, Danny Flaherty) watched as an addled judge named Julius Hoffman (Frank Langella) heaped contempt charge upon contempt charge on them and Kunstler (Mark Rylance).

Not that Judge Hoffman wasn’t often provoked: While Hayden tried his best to play it straight, believing reason and rectitude could win over the jury, Abbie Hoffman and Rubin used the courtroom as a backdrop for profane improv and antic agitprop, arriving one day in judicial robes (under which they wore Chicago police uniforms), and on another with a birthday cake. As if the obvious bias of the judge wasn’t challenging enough, the defendants - especially Hayden and Hoffman - were squabbling among themselves over tone, tactics and revolutionary bona fides.