Lyndon Baines Johnson has been a hot commodity of late, at least in the entertainment world.

Liev Schreiber took at stab at portraying the 36th president in the 2013 film “Lee Daniels’ The Butler.” In 2014, Tom Wilkinson played LBJ in “Selma.” Last year both John Carroll Lynch (in “Jackie”) and Bryan Cranston (in HBO’s “All the Way”) played versions of the late commander in chief. Each portrait had its upside.

But I suspect that none of these actors had as much fun bringing to life the cagey and colorful political vulgarian as his fellow Texan, Woody Harrelson, seems to be having in “LBJ,” crudely and rudely drawling his lines behind a wall of latex makeup, plus-size prosthetic ears and horn-rim glasses that obscure his own facial features.

It’s a kick to watch Harrelson’s blustery good ol’ boy threaten to take a hatchet to one underling’s male member after the aide fails to deliver an exact vote count on a bill, and later, as he indulges in a leisurely open-door bathroom break during a meeting with two political advisers. Yet director Rob Reiner keeps the movie surrounding these shenanigans reined in.

The result feels like an installment of a 1980s miniseries that’s been preserved in amber rather than a complete and fulfilling production. Punctuated by regular flash-forwards to Nov. 22, 1963 — when President John F. Kennedy was assassinated — the film presents a mostly linear account of how Johnson went from losing the 1960 Democratic presidential nomination (to JFK) to becoming Kennedy’s running mate — before finding himself seated in the Oval Office after Kennedy’s death.

As “LBJ” tells it, the New Englander brought sex appeal to the ticket, while the Southerner provided experience in the trenches. Together, this odd couple fought to deliver a progressive agenda that initially pivoted around what would become the Civil Rights Act of 1964. But, suddenly, LBJ had to fly solo, and steady a grieving nation.

Given the recent sharpening of racial tensions and violence, it’s easy to imagine why a Hollywood liberal like Reiner would focus on that part of Johnson’s legacy — rather than, say, Johnson’s escalation of the Vietnam War, which would prove to be LBJ’s downfall. Buttressed by a sly, low-key performance by Jeffrey Donovan as JFK — who rejected the distrust of Johnson by his attorney general, and brother, Bobby — Hartstone’s story suggests that this political alliance was just the start of a mighty partnership that ended too soon.

If “LBJ” feels stunted as a film, it compensates with some fine acting: Jennifer Jason Leigh, sporting a bouffant hairdo, transforms herself into Johnson’s supportive wife, Lady Bird. And the ever-reliable Richard Jenkins is a standout as Johnson’s N-word-spouting friend, Georgia senator Richard Russell Jr.

With chaos all too regularly consuming the current White House, there is a sweet nostalgia in savoring how government is supposed to work.

At the same time, it’s telling that the one real lump-in-the-throat moment arrives in the form of an archival news clip, as TV anchor Walter Cronkite struggles to share the news that Kennedy has died. If we can survive that, the film reminds us, we can get through almost anything.