- "Is there something that the Russians have on him," Murphy asked
- Critics said Trump recently suggested that the U.S. behaves similarly to Russia
"This is as scary as it gets and they need to get to the bottom of what this is all about," the Connecticut Democrat told CNN's Alisyn Camerota on "New Day." "What is this strange relationship between Putin and Trump? And is there something that the Russians have on him that is causing him to say these really bizarre things on an almost daily basis?"
Trump appeared to equate US actions with the authoritarian regime of Russian President Vladimir Putin in an interview released Saturday.
Trump told Fox News' Bill O'Reilly that he respected his Russian counterpart.
"But he's a killer," O'Reilly responded.
"There are a lot of killers" Trump replied. "You think our country's so innocent?"
The President has been criticized by both Republicans and Democrats for suggesting that the American government behaves in a way comparable to Russia's.
"If you want to believe the worst here, if you want to believe that Putin is literally pulling the strings of this administration, then this is exactly how it would play out," Murphy said. "You would be making moral equivalences between Putin's killing of journalists, political opponents and U.S. military activities."
The lawmaker also said Trump has downplayed Russia's offenses in eastern Ukraine and hinted at withdrawing sanctions from Russia.