Not really true. In this case he doesn’t have the power to do it because the federal government doesn’t operate elections. He has no lever to pull.

At most he can convince some friendly state legislatures to ban mail-in voting, but even that may not be an automatic process (e.g., maybe some states have requirements to change the constitutional or put the item up on a ballot measure).

Every Trump policy to this point has involved some kind of lever that the executive branch has had power over: tariffs, national guard deployments, and even in the case of ICE enforcement, Trump had to go to Congress to appropriate additional funding to make that viable long-term.

As an aside, I’m not personally too worried about the mail in voting as a hot button issue. I don’t think Republicans will touch it significantly because they need turnout, too, and they need it from key demographics that use absentee ballots like older voters and military members.

Some research seems to show that mail-in voting doesn’t really benefit a specific party.

https://www.dw.com/en/us-election-mail-in-voting-biden-trump...