Washington CNN  — 

House impeachment manager Zoe Lofgren said Sunday she hopes Republican senators who have disagreed with a quote during the House’s opening arguments won’t let it solely shape their decision on whether President Donald Trump committed high crimes or misdemeanors.

Asked by CNN’s Jake Tapper on “State of the Union” if it was a “mistake” for California Rep. Adam Schiff, the lead Democratic impeachment manager, to quote a CBS News report during the final day of his team’s opening arguments, Lofgren, also a California Democrat, said she doesn’t know if it was.

“But hopefully the senators are not going to be letting a – quoting a CBS report which Adam himself said (he) didn’t know if that was accurate in making a decision for the country in whether the President has committed high crimes and misdemeanors,” she said. “I can’t believe the President’s misbehavior would be ignored because of something like that.”

On Friday, Schiff cited the report that Republican senators had been told “your head will be on a pike” if you vote against the President. The comment sparked an audible reaction from Republican senators, and upset two of the key Senate Republican votes, Susan Collins of Maine and Lisa Murkowski of Alaska. Following the remarks, Collins shook her head and said, “That’s not true.”

“He was doing fine with moral courage until he got to the head on the pike. That’s where he lost me,” Murkowski said of the comments.

Appearing on the same program Sunday, Republican Sen. James Lankford of Oklahoma also criticized Schiff for quoting the report, telling Tapper that he and other senators were offended by the move.

“The offensive part is there is he was saying that the President had communicated to us that our heads will be on a pike if we oppose him, and all of us looked at each other and we have heard no such comment from the President,” Lankford said.

“This is a side show in the whole thing,” he added. “We were just offended in that he’s ending his closing arguments by saying you’ll have to vote the way you are because the President is saying to you ‘I’ll put your head on a pike if you don’t’ and we all know that is not true.”

Schiff defended his comments on Sunday against the Republican criticism, saying he doesn’t think he got too personal in citing the report.

“What may be personal, though, and I think I have to be very candid about this, is I made the argument that it’s going to require moral courage to stand up to this President,” he told NBC. “And this is a wrathful and vindictive president.”

Republicans and Democrats have so far been divided along party lines on the issue of including witnesses in Trump’s trial, and Schiff’s comments could alienate any of the four key Republican senators the House managers are looking to convince to vote in favor of having witnesses. Last week, the Republican-controlled chamber approved rules for the trial that delays the question of whether the Senate should subpoena witnesses and documents until later in the trial.

On Monday, the President’s legal team will continue their opening arguments before the chamber.

CNN’s Jeremy Herb and Manu Raju contributed to this report.