At some point, the new movie about blacklisted screenwriter Dalton Trumbo has to deal with his Communist beliefs, and that's when things get cheesy.

Trumbo's daughter asks: Gee, dad, what's a Communist?

Trumbo (Bryan Cranston) explains: If you have a cheese sandwich, and you give a hungry classmate half your sandwich instead of charging him for it, you're a Communist.

And that's it - the extent of the movie's interest in Communist ideology.

You wait in vain for a scene in which the girl says, "Dad, when did Josef Stalin's half a cheese sandwich turn into labor camps, starvation, relocation, collectivization and 20 million dead Soviets?"

Maybe it was too much to sandwich in.

So, we're left with exposition that treats us like one of the Cleaver kids.

It's a flaming irony that this horribly written scene turns up in a movie about a talented screenwriter. Another one - Trumbo, Hollywood's most famous Communist, turns out to be a much more appealing capitalist than anyone in those "Atlas Shrugged" movies.

Banned from Hollywood, jailed for thumbing his nose at the House Un-American Activities Committee, Trumbo fights back with a creative money-making scheme that can be described only as entrepreneurial.

Disruptive, one might say.

In fact, he becomes an Uber-like hub, matching other blacklisted writers with scripts that need writing or ghost-writing. At one point, Trumbo even says that the blacklist writers survive because the black market thrives - a backhanded nod to unfettered markets.

"Trumbo" has its ups and downs, but this portion of the movie is fun. Big Hollywood studios won't hire him, but Trumbo finds willing partners in independent B-movie producer Frank King (John Goodman). It's not glamorous work - King is the kind of guy who commissions a movie about a gorilla because he bought a gorilla suit.

But it pays, and Trumbo is game, and brings in other blacklisted communist writers (Louis C.K., Alan Tudyk) to write other low-budget films. Here the movie seems close to making some observations about elitism and class - the egghead Commie writers want to know an alien's motivation for impregnating a human girl, and King must explain actual proletarian tastes.

The movie is directed by Jay Roach, he of "Austin Powers" and "Meet the Parents," and you can see he's most comfortable in scenes that look for something funny in Trumbo's situation.

The movie, though, is bumpy and uneven and stiff and unsteady as drama. We never really accept the fake period pageantry of "Trumbo," and the movie feels opportunistic - one of those end-of-the-year Oscar-baiters designed to make Academy members feel awesome about show biz.

It ends with Golden Age legends standing tall against censorship and tyranny. Kirk Douglas (Dean O'Gorman) helps break the blacklist by hiring Trumbo openly for "Spartacus," and the unofficial end to the blacklist occurs when Jack Kennedy attends a screening and pronounces the movie awesome.

It's the death knell for the blacklist and its proponents, represented here by feared Hollywood columnist Hedda Hopper (Helen Mirren). Mirren is good, but it's a little strange that "Trumbo" gives anti-Communist grandstanding a female face.

Cranston is theatrical and showy as Trumbo - his performance seems to come though his cigarette holder.

If anyone gets a nomination for "Trumbo," I hope it's Goodman, as wanton panderer King.

"I'm in it for the money and the [sex]," he bellows, as King.

That's the most honest thing you'll hear in one of these movies about movies.