From an interview with GQ Magazine:
Last June, when The Washington Post published an op-ed suggesting he could be a viable candidate, Johnson posted a screen grab and gave the idea a boost. On Instagram, he called the Post piece “interesting” and “fun to read,” adding that “the most important thing right now is strong honest leadership from our current and future leaders of this country.”
Since then, Johnson tells me, he’s given the question more thought. “A year ago,” he says, “it started coming up more and more. There was a real sense of earnestness, which made me go home and think, ‘Let me really rethink my answer and make sure I am giving an answer that is truthful and also respectful.’ I didn’t want to be flippant—‘We’ll have three days off for a weekend! No taxes!’”
So, after all that consideration, Johnson doesn’t hesitate when I ask him whether he honestly might one day give up his life as the highest-paid movie star on earth—which is unquestionably easier, more fun, and more lucrative than being president of the United States—in order to run for office. “I think that it’s a real possibility,” he says solemnly.
The full piece is actually pretty entertaining.