While there is no evidence of significant voter fraud on the part of individuals, election fraud has been a problem in every election where the vote count is done behind closed doors or inside a black box.
We did not have a President from the time W was sworn in until he was finally gone; we had an unelected Acting "President", put in place by a corrupt Republican-packed Supreme Court on the fraudulent basis of rigged elections, especially in the Banana Republic of Florida run by W's brother Governor Jeb, and in Ohio where the statistical impossibility of the variance between the official election results and the exit polls has never been refuted.
This result didn't make the Republicans any worse than the Democrats; it just meant that in this instance the Republican election-fraud machines outperformed the Democrat election-fraud machines.
Now we have another illegitmate Acting "President" put into office by crooked Republicans with help from the enemy Russian government and the criminally flawed Electoral College. It is our further misfortune that Donald Trump is mentally ill and guided only by greed and self-delusion, naturally surrounding himself with his family and other parasites who feel entitled to treat everything and everyone, including each other, as nothing more than resources to be exploited for personal gain, consequences be damned, perfectly willing to leverage middle-class frustration to allow them to commit outrage after outrage.
No public official who supports the purchase of any electronic voting device designed without a paper trail has any business holding office, then, now, or in the future. The only reason for installing voting machines without a paper trail is the hope that one's own party's election-fraud machines will outperform everyone else's election-fraud machines.
There is no excuse for acceptance of an insecure voting system or gerrymandering. See Secure Voting System.