The No. 2 Democrat in the Senate said Sunday that members have "gone too far" in hinting how they plan to vote before the impeachment trial has begun in the chamber.
Senate Minority Whip Dick Durbin of Illinois specifically called out Senate Majority Leader Mitch McConnell and Republican Sen. Lindsey Graham, who have both said they won't be impartial or fair jurors, because they believe the impeachment process is political.
"How can they hold their hands up and say I swear impartial justice, I'd would like to sit at the manager's table with the President's team? You can't do that. They shouldn't have done it," Durbin told CNN's Dana Bash on "State of the Union."
When Bash pointed out that Democrats have done the same, Durbin replied, "Well they shouldn't."
"As far as I'm concerned, they can tell which way they are leaning or how they feel in terms of the probability, but when it comes to saying I've made up my mind, it is all over, for goodness sakes, that is not what the Constitution envisioned," Durbin, who was also in the Senate during the Clinton impeachment trial, argued.
"Alexander Hamilton said we give this job to the Senate because they are quote independent and dignified. For goodness sake, let's do our best to meet those standards," he added.
On Wednesday, the House voted largely along party lines to impeach President Donald Trump. A Senate trial is expected to start next month, but House Democrats have held off on sending the two articles of impeachment, and appointing impeachment managers, to the Senate -- saying they won't do so until they see a "fair" structure for the trial.
The Senate's impeachment trial of Trump is likely to end with his acquittal since conviction would require 20 Republicans to side with Democrats. There's no sign that any Republican senators are ready to vote to remove Trump from office.
Durbin said on Sunday that Democrats are hoping for the support of at least four Republican senators, believing it could make a big difference. But Durbin said he has not yet identified those four GOP senators.
"I've not whipped them, or twisted their arms, or asked hard questions," Durbin said. "I've spoken to a few of them. They tell me the political circumstances now in the Republican caucus are really very extreme in terms of this loyalty to the President no matter what."