"There are very few written rules around here," Blumenthal said. "The most important rules are the unwritten ones. The most important of those ones is, you keep you word."
Blumenthal pointed to Republicans' wholesale refusal to consider President Barack Obama's choice of Merrick Garland to replace the late Justice Antonin Scalia.
"Members of this committee on the other side promised, when Merrick Garland's nomination was given no hearing, no vote, members would not even meet with him, that never would a Supreme Court nominee be considered during an election year. You are breaking that word."
Blumenthal added that Republicans on the committee were moving ahead fully aware that they were in the wrong.
"You are moving ahead with this nomination because you can. But might does not make right," he said.
"In your hearts you know that what's happening here is not right. It's not normal."