See Canada for an example of an independent federal institution overseeing the elections, see https://www.elections.ca
The decentralized election system of the US is extremely resilient to tampering from the top. I personally believe the decentralized nature of the US election system is vital to its democracy. Think of the decentralized election system as a check and balance on power rather than a fair count of each person's vote. That said, I think the US needs to do away with the electoral college middlemen and replace it with a direct vote tallied by each county that is reported by each State. The US also needs to make gerrymandering illegal