Yes it is possible but the overwhelming evidence says it didn't happen. Look at AZ that they made a big deal out of. Biden ended up with a few more votes after it was done. You don't hear a peep about that anymore. The fraud was on the R side trying to submit fraudulent electors to be certified by Pence.
So we're on the same page for the most part, great, now don't you think it would be great if you had confidence in our elections, and you could say with near certainty "it's impossible"?
That's why we need to be careful with the laws, and that's why we need ID.