“The president would be best served by letting his lawyers speak for him and not doing any comment. At all,” concurred Sen. Susan Collins (R-Maine.) “I doubt, however, that he will heed my advice.”

Trump has not exactly hid his feelings about the House impeachment proceedings, often tweeting that it’s “phony” and a “hoax.” The president even posted tweets attacking several witnesses who testified during the House’s impeachment inquiry. And if he continues the barrage during his impeachment trial in the Senate, it could derail the Senate GOP’s strategy, annoy undecided senators and end up hurting his efforts to win unanimous acquittal from the Republican Party.

Trump has a history of damaging his own arguments among the people whose support he needs most. During Brett Kavanaugh’s arduous Supreme Court confirmation amid sexual misconduct allegations, Trump weighed in and made his party’s efforts more difficult. One tweet in September 2018 read: “I have no doubt that, if the attack on Dr. Ford was as bad as she says, charges would have been immediately filed with local Law Enforcement Authorities by either her or her loving parents,” referencing Christine Blasey Ford, the woman who accused Kavanaugh of sexually assaulting her when they were teenagers.

With the House impeaching Trump Wednesday, the Senate will likely take up an impeachment trial in early January. It will be the first time the Senate holds an impeachment trial in the age of Twitter and social media — and with a president who can provide real-time commentary while senators are confined to the Senate floor.

“Tweet less, smile more.” Sen. Shelley Moore Capito

Senate Republicans have complained for four years about Trump's tweets. But with the remarkable drama of a Senate trial impending, even his closest Hill allies say the president could benefit from a Twitter vacation.

“He needs to be respectful of the process,” said Sen. Lindsey Graham of South Carolina, one of Trump’s most vocal defenders in the Senate. “He can defend himself, he has a right to express his grievances but if I were him I would … keep a low profile.”

Trump, however, is as far from low profile as it gets, furiously posting as many as 100 tweets a day during the House’s impeachment proceedings. And what he says can create an instant controversy his party must deal with, such as when he compared impeachment to a “lynching” or when he tweeted that four Democratic minority congresswomen should “go back” to where they came from despite being U.S. citizens.

“There [are] many cases in which I hope he doesn’t tweet,” said Senate Majority Whip John Thune (R-S.D).

“Tweet less, smile more,” Sen. Shelley Moore Capito (R-W.Va.) advised, riffing on a line from the hit musical “Hamilton.” ”It does make it more difficult but he’s going to do what he’s going to do.”

The White House did not provide comment.