2 major factors.
1) Voter registration.
- You need a government ID to register and you register a signature when you do it.
- In order for someone else to steal your vote in person they'd not only need to know your name and district but they'd have to be roughly the right age and sex and know how to recreate your signature to a minimally acceptable degree.
- When you vote, you sign a form which functionally "consumes" that vote. So if you've signed for someone else and they show up, there's an instant flag for a probable fraudulent vote. There's a process that gets kicked off to find out what's happened.
- Mail in ballots are numbered and assigned to a specific voter so they can't be reproduced and are flagged on the voter rolls so they can't vote again at the polls. There are measures for dealing with conflicts there too.
2) The risk to reward ratio is
insane.
- A fraudulent vote is 1 to 2 years in prison and disenfranchisement.
- Every time you voted illegally you'd risk up to two years in prison that earns your candidate one vote.
- And of course in a state that's pretty evenly split you'd probably see a net equivalent fraudulent vote count for each party really nullifying the reward. In lobsided states it's clear who's gonna win this nullifying the reward.
- The rate of conviction is VERY high for this as well. Conservative think tank The Heritage Foundation (the project 2025 people) keeps a database that goes back to the 90s. There are 1561 cases of proven voter fraud and 1325 convictions.
- Anyone on the ballot can challenge the outcome to an audit creating massively heightened risk of exposure.
So yes, there are instances. Someone fills in their dead mom's mail in ballot, or votes for a neighbor that moved, a disenfranchised person who wasn't scrubbed from the voter rolls shows up.
For an organized effort to swing a state youd need to find and organize thousands of people per state, probably tens of thousands because you don't actually know how many you need until it's already over.
- They must all be willing to risk prison.
- They'd need to know the name of a registered voter approximately their age who is absolutely not going to show up.
- They need to know where that person's polling station is.
- They need to be sure that none of the pollsters, who are typically locals, will recognize them or the person they are impersonating.
- They need to know what that signature looks like (within reason).
- You'd need every one of the co-conspirators to be able to keep a secret perfectly without exposing the conspiracy.
- AND you'd need to do that without anyone, including the organizers, leaving any paper trail or financial records.
Basically it's nearly impossible to swing a US election with fraud at the polls, and people caught trying are convicted, so no one bothers.