In an interview on ABC News' "This Week" on Sunday, Connecticut Democratic Sen. Chris Murphy warned of an "assault on the Constitution" under President Donald Trump.

"I think this is the most serious constitutional crisis the country has faced, certainly since Watergate," Murphy said. "The president is attempting to seize control of power, and for corrupt purposes."

Murphy called the turmoil inside the U.S. Agency for International Development a "red-alert moment" for the country, and a signal that Trump is ushering in "the billionaire takeover of government."

"The president wants to be able to decide how and where money is spent so that he can reward his political friends, he can punish his political enemies," Murphy said. "That is the evisceration of democracy."

This is a developing story. Please check back for updates.