TORONTO - Bryan Cranston had to play it big in Trumbo because, well, Dalton Trumbo was big.

The Hollywood screenwriter, blacklisted in the late 1940s but determined to keep his family fed and clothed by cranking out screenplays under a cloak of pseudonyms, was a force to be reckoned with. He was bullish and voluble. He smoked. He drank. He was not shy with his opinions.

"He was a very flamboyant man," Cranston said, "and I was concerned, because of the cigarette holder, because he had this lilt to his speech - he would go up and then he'd go down - and because of the bird on his shoulder."

Yes, a bird - a parrot named Sammy, given to Trumbo by Kirk Douglas. Trumbo, which opened Wednesday and has prompted talk of an Academy Award nomination for its star, is not the story of a humble, retiring gent.

For Cranston, that represented a tricky balance: How to play this larger-than-life figure so he still appears true-to-life? Not an exaggeration, not a cartoon.

"He was big, he was theatrical, he was dramatic," the actor said in September, when Trumbo premiered at the Toronto International Film Festival. "And he loved the idea of people listening to his wordsmith musings. So, at the risk of jumping into the deep end and being swallowed up, I thought that was the only way you can play him. Big."

Cranston, 59, who started in TV in the 1980s (among his many credits over the ensuing years: Tim Whatley, "Dentist to the Stars," in several seasons' worth of Seinfeld), has certainly played big before.

Walter White, the high school chemistry teacher turned meth king of the breakthrough series Breaking Bad, was no wallflower. Nor was Lyndon Baines Johnson, the 36th president of the United States, whom Cranston brought to Tony-winning life on the Broadway stage in All the Way.

"There are actually a lot of similarities between Dalton Trumbo and Lyndon Johnson," noted the actor, who has put the LBJ prosthetics (nose, earlobes, chin) back on for an HBO adaptation of All the Way, to be telecast next year.

"Both men are incredibly ambitious, both were very prolific and astute - and at the top of their game in their chosen professions," he said. "Both were damaged, to some degree - empty vessels in some areas, [with] a need to be accepted, a need to be validated, and a need to be approved. But righteous, and never backing down from a fight."

Trumbo's fight, depicted with a jaunty, old-time Hollywood flair in the Jay Roach-directed feature, was against the House Un-American Activities Committee, which summoned the writer to testify for his alleged Communist leanings. Cited for contempt of Congress, Trumbo spent 11 months in a federal prison.

His fight, too, was against Hollywood right-wingers such as John Wayne and columnist Hedda Hopper (played by Helen Mirren), who pressured the studios into refusing to hire Trumbo and other writers, directors, and actors suspected of having Communist sympathies.

"It was such an important, dark period in American history - where a man goes to prison not because he committed a crime, but because the powers that be didn't appreciate, or didn't like, the answers they were getting from him," Cranston noted. "People need to be reminded that in any given time in our history - and going forward - there are periods like these when we need to look at not just the First Amendment but look at the Constitution. We need to say, 'This is what we are, this is what represents us, this is how we want to live.' "

In Trumbo, Diane Lane is the screenwriter's put-upon wife, Cleo. Elle Fanning plays their teenage daughter, Niki, in the latter half of the film. An array of actors show up as Tinseltown figures of the day: John Goodman as the low-budget movie producer Frank King, who gave Trumbo work; Richard Portnow as MGM head Louis B. Mayer, who took the work away from Trumbo; Michael Stuhlbarg as Edward G. Robinson; David James Elliott as Wayne.

Dean O'Gorman plays Kirk Douglas, the dimpled-chinned movie star who, in 1960, publicly acknowledged that Trumbo was the author of the Oscar-winning gladiator epic Spartacus, thereby effectively ending the blacklist that had killed careers over the course of more than a decade.

After shooting Trumbo, Cranston got to meet with the real Douglas, who had been shown the film.

"He said he really liked the film and enjoyed the film," Cranston reported. "But he said he had one problem, and I braced myself, and I said, 'What was that, Kirk?'

"And he said, 'I don't understand why the filmmakers didn't consider hiring me to play Kirk Douglas.' "

Cranston laughed then. And he laughed again as he recounted the story.

"Douglas took great risk in what he did, and Spartacus was the first time that Dalton Trumbo saw his real name up on screen in over 13 years. And it did collapse the blacklist, and Douglas is owed a great deal of thanks for his courage."

And how is Douglas now, the three-time Academy Award nominee, Lifetime Achievement Oscar recipient, and Medal of Freedom honoree?

"He's going to be 99 at the end of this year, but there's still a stateliness, you can see that there's that Kirk Douglas of old, steely and stout," Cranston said. "And yet his body is 98 years old, and so inside he's battling. But it's as you would expect Kirk Douglas to battle, and I think some days are better than others."

Over the years, and over a career that now boasts more than 140 film and TV credits, Cranston has learned to leave his characters at the door when he comes home at night. Even with roles such as Trumbo, LBJ, or Walter White, which require enormous amounts of energy and emotional investment, the actor gets to a point where he can leave them behind. There's the initial period, the research, the character development that can be challenging, but then, he says, he's fine.

"Comfortable shoes aren't that way when you first put them on," he explained. "It takes a while. And so, when I'm developing a character like LBJ or Dalton Trumbo, when I first put on those shoes, I feel it more. . . . Sometimes, I'll take home Dalton's irascibility or LBJ's mercurial nature, and my wife will go, 'OK Lyndon, or Dalton, why don't you calm down?'

" 'I'm not being that way!'

"'Oh yes, you are.'

"It's not until you're up on stage and doing it for awhile that you can slip out of those shoes at the end of it and leave them at the theater. And the same in film, when, over the course of three months when you're shooting, I can say, 'Oh, are we ready? Well, let me slip into those shoes.'

"Same thing with Walter White when I was doing him. He got to be so comfortable that when I took off his clothes, the Wallabees and the Dockers, and took off the hat and the glasses and took the makeup off and everything - I left him at work."

And he hasn't come back, late at night, to haunt?

"No, no. Breaking Bad came to such a satisfying conclusion, to me - we had a fully realized beginning, middle, and end.

"I've been asked, 'Would you like to do a Breaking Bad movie? Would you want to do Walter White again?' - and we don't know, in truth, if he truly was dead.

"And I say, 'No.' I'm satisfied. It's almost like having a delicious meal: Wine with dinner and you have the salad, or soup, and you have a dessert and a little coffee afterward and Ah, that's very satisfying.

"And you're finished with that, and then someone says, 'Here's another dessert.' And you go, 'No, really, thank you.'

" 'No, no, here, have it.'

" 'No really, I'm fine. I'm done. I so enjoyed it.'

"If I tried to eat another dessert, it would diminish the experience I had of the meal. It's like staying too long at a good party, and all of a sudden the energy changes and you go, 'Oh, I should've left an hour ago.' "