Zachary Quinto is pleased Barack Obama is a big Star Trek fan because of his stance on gay marriage.
The 35-year-old actor, who came out in 2011, has famously supported Obama's re-election bid by manning phones and appearing in campaign videos.
He said: "We live in an age when for the first time a sitting American president has called for marriage equality. I felt that it was imperative to get involved.
"I subsequently got to meet him at a private event and had the chance to have some words.
"He asked about the new movie. He's clearly got his finger on the Star Trek pulse."
Zachary, who starred in cult TV series Heroes, had found out the president was a Trekkie at a previous meeting.
He said: "It was the first time I met him, at a fundraiser. The president was walking through the crowd, shaking people's hands as he went.
"I was about four or five people deep, about an arm's length away. He looked up and saw that it was me, and he gave me the Vulcan salute. I have never felt cooler being Spock than in that moment."
Zachary said it was a nerve-wracking experience acting opposite Leonard Nimoy on the Star Trek set, who had casting approval over who would play his younger self: "The most profound moment was when Leonard and I both walked on set in our Spock make-up. Then it was unavoidable: 'This is happening to me'."