Here are just a few. Do your own research and you'll find more. And these are just the ones that made the news. You don't think this goes on? Here in Oregon the Secretary of State finally had to admit that they'd found over 1000 illegal immigrants who had received ballots in multiple elections. They did not pursue that investigation further - yeah, we're a blue state - but with mail-in ballots it's so easy for this stuff to happen and not be detected. Yes - we need the Save Act. Only US citizens get to vote in our elections!
https://www.dhs.gov/news/2026/03/09/ice-arrests-criminal-illegal-alien-who-voted-seven-federal-elections-2008 https://www.justice.gov/usao-nj/pr/aliens-charged-illegally-voting- https://www.ice.gov/news/releases/19-foreign-nationals-indicted-illegally-voting-2016-electionsfederal-election-and-making-false-statements-while 
