Sen. Susan Collins wrote note to Chief Justice Roberts prior to his admonishing of Senators

Christal Hayes, USA TODAY

Sen. Susan Collins, R-Maine, said she was "stunned" by remarks given by House Judiciary Chairman Jerry Nadler at the start of the trial, where he accused senators of being complicit in a cover-up if they shot down measures to hear from additional witnesses.

Collins, a key moderate who Democrats are hoping to convince that more witnesses should be heard from during the trial, said the remarks caused her to write a note to Chief Justice John Roberts, asking whether the Senate's rules had been violated.

"I was stunned by Congressman Nadler’s approach, and it reminded me that if we were in a normal debate in the Senate, that the rule will be invoked to strike the words of the Senator, for impugning another Senator in this case," she explained in an interview with Politico, remarks that were confirmed by her office. "So, I did write a note raising the issue of whether there had been a violation of the rules of the Senate."

Collins said she gave the note to Laura Dove, the secretary for the Senate majority. Shortly after the note was delivered, Roberts admonished both house managers and Trump's counsel for the testy back-and-forth. "I was glad that he did," Collins said.

Democrats continued detailing their case against President Donald Trump as the Senate impeachment trial resumes Thursday and were expected to focus on the Constitution and the legal grounds for the president's removal.

This article originally appeared on USA TODAY: Trump impeachment: Susan Collins wrote note to Justice Roberts