There's a law that says the department of justice has to pre-approve election changes in some states with a history of violating voting rights, but our illustrious supreme court has ruled they don't have to follow it anymore.
What I meant is that if you look at Canada for example, provincial elections are separate from federal elections and the federal government manages its own elections and the provinces aren't involved at all (it's even seen as a faux pas for a premier to tell people who they would rather see in power at the federal level).
Donnie wouldn't have been elected in the first place with a fair system. Also you make it an independent non partisan agency so the president can't interfere.