I disagree with this approach without even touching the morality aspect.
There should be no way to lose your voting rights once you are of age and a citizen of the US for the very simple reason of limiting the bureaucratic overhead of elections. If every citizen above the age of 18 can vote, you can just completely remove the ridiculous notion of “voter registration”.
Just register everyone based on their legal address (which the government should have anyway because taxes). Just like a real democracy.