Sen. Richard Blumenthal is responding to a push this week by President Trump to nationalize elections.
Blumenthal said the proposal would take control of political races away from states and place it with the federal government.
"Donald Trump is literally shouting the quiet part out loud, suggesting a totalitarian takeover of elections by his administration," Blumenthal said. "It is without a scintilla of evidence that there needs to be federal intervention and contrary to the Constitution."
Blumenthal said there is growing support among some Republicans in Congress to formally oppose the effort.
He said the proposal would shift authority traditionally held by states to the federal government.