He has tweeted he will launch a federal investigation of voter registration issues such as people being registered in more than one state (as when they move), or the names of the dead being left on rolls.
These create opportunities for fraud not specifically related to aliens voting.
But you have to know who has moved or died, where they live, whether they are still registered, and so on.
As it was notorious the long ago Mayor Daley of Chicago certainly did, though I don't recall any hint aliens were involved.
And generally registrations lapse if a voter misses a few elections, anyway.
Is there a problem, or even a possibility, of aliens registering to vote?
They would then show up to vote in their own names.
No impersonation involved.
Update, 1/26, 0023 hrs EST.
Turns out states screen new registrants in various ways to be sure of citizenship.
So aliens registering and then voting is not likely a big issue.
Just doesn't look good for that 3 to 5 million claim of The Duce's.