Trump has little to no control over elections. There isn't much he can actually do to stop elections. States run elections, not the federal government.
He tried, or did you forget his 2020 calls to Georgia's election officials to find him a few hundred votes in key districts?
Why stop elections, that's too overt and obvious and clearcut. The person in charge of state elections has a lot of leeway on how to influence an election. They control which precincts are closed & opened, which means they can ensure lines are too long for people to wait in in blue areas, and only 15 minutes in red areas when it can make a material difference in an election. It's already been done, we've seen it on the news in the last I dunno-how-many Presidential elections.
We saw it in Texas where state Republicans changed the voting law so that counties can now only place a SINGLE legal ballot box to drop off mail in ballots. Imagine that, a single place to drop off your vote that could potentially be a three hour drive, and has to serve a county with a population size anywhere from 2 up to 5 million people. It's a great way to quash blue voters in mostly blue cities to influence red state elections. The Texas supreme court upheld it, too. Yet states on the west coast seem to have ballot dropoff boxes that outnumber even the blue USPS mailboxes. Texas did this in the name of elections integrity just before the 2024 election, you see.
State election officials in dozens of states have been replaced with pro-MAGA individuals. They can easily adopt other methods to influence elections, such as throwing out voter registration rolls, changing staffing levels (and # of voting machines) allocated to individual precincts, or sneakily changing the rules to unregister people that haven't voted in the previous X number of elections. Texas has done all this before, such as they changed the rules to purge 'inactive' voters and subsequently dropped more than a million names off the rolls just before the 2024 election. Texas also adjusted voting laws so that when doing vote by mail, signatures have to be applied in multiple places including externally on the mailing envelope. Since many people didn't sign the mailing envelope itself their mail-in ballots were rejected.
How about an easier scenario.
The Justice Department has asked states for their voter rolls with an eye toward purging ineligible voters Texas already handed them over and begun purging yet more people off the state voter rolls. If your state purges you off the voter registration, are you guaranteed to be notified? In most cases you are not, and when you find out by showing up to vote it's already too late to reregister. You can cast a provisional ballot which are handed out to placate people, but those are not usually counted without good cause, and failing to be registered is not one of them. The Trump administration has already proven all the people running it are liars, it wouldn't be a stretch for someone to intentionally or otherwise pass on misleading information to a state, and the state itself then incorrectly purges legitimate voters off the state's rolls. What seems like an insignificant number of voters at the state level would still be enough to swing a single county's results.
MAGA has taken unprecedented power over state voting systems in this country. But even before that votes have been influenced, remember the whole hanging chads affair? Votes were being tossed out because of how many corners the chad was hanging from. More votes were being tossed out because signatures didn't match... people used print in one, but cursive in another. Used initials in one, yet spelled their name out in another. Used a middle initial in one place, but not another. They came up with all kinds of justifications for tossing out votes, and if SCOTUS hadn't intervened things would've continued to degenerate.
Hell, if you look at the street sign on both ends of my block, the name ends in Drive. But if you try to mail me something then USPS, Fedex, Google maps, and the entire world will correct the street name to Road. In a digital world of information there's plenty of ways to adjust rulesets to disqualify someone when something doesn't perfectly align or match up, and with the feds now perusing voting registration rolls and comparing the data across all existing government databases, you can expect mismatches to occur. So even when there are no nefarious intentions at all people are going to be at risk of being erroneously purged from state voting rolls if their state agrees to hand over voting registrars to the Trump admin.
One might scoff at having to register to vote as being an inconvenience, but in Texas there's no way for us to register to vote online. That option was removed decades ago. And since there are existing deadline dates you must register before to even vote in elections, there are a lot of hurdles for anyone stuck trying to register last minute to vote here. And again, in Texas if you are de-registered you're not guaranteed to be informed about it either.