It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
FactCheck.org "monitor[s] the factual accuracy of what is said by major U.S. political players in the form of TV ads, debates, speeches, interviews, and news releases". This collection of articles covers politicians' claims about widespread voter fraud.