The reason I'm not worried: election workers are paired up with the opposite party so for every republican official, there's a democrat official. My mom works the polls and said the republican person constantly will give out bad information, she will challenge it, then the officials come in and rule in her favor because she's legally right. For instance in most states if you show up at the wrong polling place you can fill out an affidavit and still vote. Or if you don't have your ID in a state that requires it, many states will still allow you to vote as long as you provide proof of ID within a certain amount of time.
I'm also not concerned about the certification process after congress changed the rules a couple years ago
Congress on Friday gave final passage to legislation changing the arcane law that governs the certification of a presidential contest, the strongest effort yet to avoid a repeat of Donald Trump's violence-inflaming push to reverse his loss in the 2020 election.
www.pbs.org
Will a group of republicans try to deny Harris? Sure. But they won't have the numbers. That being said the true issue is that as VP, Harris will be there presiding over the certification.
If she wins she will certify her own win and that's definitely going to drive republicans insane over the next four years lol.