Apologies for mounting a personal hobby-horse again.
The websites Voter Fraud Clearinghouse (Democratic-leaning), and HobbsOnline (Republican-leaning) contain a wide selection of reportage on alleged voting fraud.
If even half the stories are true, it says a lot about the perversion of democratic governance that partisan office-holding covers in the US. Aside from the accusation-slinging, a good number of frauds and perceptions of fraud could be controlled by appointing an independent body to supervise elections.