They do indeed spend a lot of time and effort not letting people do it.

https://www.aclu.org/news/civil-liberties/block-the-vote-vot...

Carlin was an insufferable cynic who helped contribute to the nihilistic, cynical, defeatist attitude to politics that affects way too many people. The fact that he probably didn't intend to do this doesn't make it any better.

“If your vote didn’t matter, they wouldn’t fight so hard to block it.”