Correct. You now have to overcome the margin of fraud. It shows up predominantly with ballots that only have votes for one or two candidates. When you see vote totals for Pres and Senator that are twice as many as for state and local candidates, you must suspect that there is something going on.

This situation in NC is as many as 35k multiple votes in NC and in another state. Only 28 states provide data on voters such that they could be tracked, so the actual number could be even higher. And this study only includes voters with a record in NC, so the overall fraud is likely significantly higher nationwide.