It already has happened. The only cases of voting irregularities have been in favor of candidates on the right. Just a few examples that have facts and data to back them up:

Lots of issues in Ohio in 2004 helped W get reelected: https://web.archive.org/web/20060614200223/http://www.iwantmyvote.com/lib/downloads/references/house_judiciary/final_status_report.pdf

Statistically fishy votes in Florida that same year: https://www.wired.com/2004/11/researchers-florida-vote-fishy/

Voter disenfranchisement in Florida swayed the election in 2000: https://www.usccr.gov/files/pubs/vote2000/report/exesum.htm

The left has allowed the GOP to get away with blatant fraud, minimally fighting back while maintaining a level of decorum, and these crazy right wingers have the absolute gall to loudly accuse the left of fraud.