Lithgow is an old pro, but he could still learn from observing other members of his profession.
Good example: Sydney Sweeney, because she's thought to be Republican leaning, often has interviewers asking gotcha questions trying to get her to make a political statement. She doesn't rise to the bait. She's there to promote a film or sell jeans or lingerie, and by golly that's what she's going to do.
Bad example: Watch an awards ceremony - we're in that season right now - and you will observe Mark Ruffalo buttonholing the first person he sees with a microphone and sharing his opinion on everything that's happening in the world. If bus drivers in Jakarta are on strike, Mark Ruffalo, the most progressive actor in the world, needs you to know that he supports them. He may not know what a Jakarta is, but he saw it on Bluesky and he needs you to know that he cares.
Actors speaking about politics, unless they're genuine experts like Richard Gere on Tibet, rarely add anything to the sum of human knowledge. Lithgow is a much loved veteran who can stay a much loved veteran just by knowing when to dodge a question.