Senate Majority Leader Mitch McConnell announced Tuesday that he'll move ahead on approving rules for President Trump's Senate trial without negotiating them with Democrats.

Between the lines: Senate Republicans' comments on Tuesday suggested that they've fallen in line with McConnell's position that the rules should be based on Bill Clinton's 1999 Senate trial, where the question of whether to call witnesses was postponed until after the start of the trial.

Many of these senators have said they're comfortable following the precedent of the Clinton trial, in which senators first gave their opening statements and submitted their questions to the chief justice of the Supreme Court before formally calling witnesses.

McConnell's move, first reported by Politico, suggests that key GOP senators are not eager to join Democrats' demands to immediately call witnesses — including subpoenaing former national security adviser John Bolton — and request new documents at the onset of a Senate trial.

What they're saying: Even Sen. Mitt Romney, who has been the most forthright in stating he wants to hear from Bolton, said he is “comfortable” with following the Clinton precedent. However, he distinguished that he is only comfortable with it because it still provides a pathway to hear from witnesses.

“I think the Clinton impeachment process provides a pathway for witnesses to be heard, so I’m comfortable with that process,” Romney told reporters Tuesday.

Other Republicans agreed. "What I want to do is what we did in the Clinton [trial]. I want to hear from the prosecution, I want to hear from the defense, and then make up our mind on that," said Sen. Chuck Grassley.

Yes, but: Some Democrats rightly point out that it’s not fair to compare the current impeachment battle to Clinton’s, as the universe of witnesses in the 1999 trial was much more defined.

House Speaker Nancy Pelosi must also transmit the articles of impeachment — which she has thus far withheld — in order for the Senate trial to begin.

What to watch: Senate Minority Leader Chuck Schumer said Tuesday that Pelosi had been waiting to send the articles until she knew what the Senate trial would look like, and that it's now beginning to take shape.

Go deeper: Key GOP senators don't want to subpoena Bolton