No. of Recommendations: 2
Even then, it's still onesy-twosy votes, like the woman who lived in a border town between CA and AZ, and voted in both states. A few dozen of those cases is not going to change the outcome, so why bother.
A few dozen votes will almost never change the outcome in a statewide election (including a Presidential election), or even most federal Congressional elections. But depending on the size of the district, a few dozen votes can be significant in smaller races. That's why many voting shenanigans will more often be seen in local elections (mayoral or city/county commissioners) or in state legislative races, particularly state house elections. It's those smaller races where voter fraud might actually play a role, not the big races.