Tim Matheson is no stranger to politics -- onscreen and off.
On The West Wing, the longtime actor -- perhaps still fondly remembered for playing Otter in Animal House -- played Vice President John Hoynes, earning two Emmy nominations for the role. Most recently, he portrayed President Ronald Reagan in National Geographic Channel's adaptation of Killing Reagan. The part earned him well-deserved award buzz, including a Critics' Choice Television Award nomination for Best Actor in a Movie/Miniseries.
"I was not politically aligned with Ronald Reagan -- nor am I today -- but you can't act politics," Matheson tells ET by phone, just a week after the election. The 68-year-old actor has made no secret of his support of Hillary Clinton or dismay over the election of Donald Trump. While he's steadfast in his own politics, which vastly differ from the likes of Reagan or even Trump, Matheson set those feelings aside to portray the president in the days before and in the aftermath of his assassination attempt by John Hinckley Jr.
"You could just get carried away or in the wrong direction if you let those things influence your performance," Matheson says, revealing that he instead focused on finding Reagan's voice. Meticulous about research, the actor studied speeches, phonetically spelling out Reagan's words in order to capture his cadence and style. He also read Reagan's diaries and autobiography. "I wanted to play the man, not the myth or the persona of who he was to so many people."
And while Matheson had preconceptions about who Reagan was, he found value in diving deep into the psyche of the president. "The biggest lesson -- which was something Reagan believed in -- is just because I don't like your politics doesn't mean I can't like you," he says. "And I find that in today's political world, that's something that's been lost."
Offscreen, when it comes to Trump, Matheson believes Reagan wouldn't be able to make sense of the incoming president. "He was a man who felt he had something to give, giving his life to being of service. It wasn't about him," the actor says. "I think that sense of selflessness and that sense of higher purpose and the greatness of American and service to America is something that's not present in this man who has been elected."
Two days after the election, still reeling from the outcome, Matheson retweeted an open letter that West Wing creator Aaron Sorkin had written to his daughter about the results. "Thank you, Aaron Sorkin," he wrote. When asked about what that letter, which expressed feelings of anxiety and guilt, meant to him, Matheson says it captured "a sense of loss and a loss of innocence."
"We're all coming to terms with it, my family and my children," Matheson continues, adding that he's shifting his focus to the day-to-day moments and personal connections. "I found that I got a bit obsessive about the politics and now that's over."
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Although he's since tweeted stories about the election results, Matheson says he's trying take a step back from what he calls Twitter's "echo chamber" of news and like-minded followers. "I've disengaged," Matheson says, revealing he felt let down by the outlets he trusted most.
In fact, Killing Reagan is a welcome respite from the current political madness, offering perspective on the situation. "What's exciting about these stories is what comes out of this," Matheson says of the film and other true-crime series. "It speaks to events like this election, semicataclysmic events like an assassination. What can we make of that? What helps us go on and find greater purpose? That's what I'm left with after the election and that's what I'm left with of what Reagan did."
With that said, could Matheson ever see himself portraying the 45th president? "You have to divorce yourself from the politics and find the character underneath," he says, pointing to Alec Baldwin's "brilliant" portrayal of Trump on Saturday Night Live. "We all, as actors, look for the greatest challenge. So, yes, I think that would be an interesting challenge. It would be a good wig, too!"