Shatner became a Naturalized US citizen in 2004 and can vote just like other citizens, but anyone who follows Star Trek knows that the original show sought to avoid politics. Also, Shatner, though choosing to speak at conservative and libertarian events has constantly maintained that he doesn't vote. My meme assumed you knew.
Star Trek Dealt with Politics (The Arena- Vietnam) And Social Problems (Let That Be Your Last Battlefield) And The place where you've gotten his citizenship status is in error! See https://www.youtube.com/watch?v=xpOMHeEQ-84