The Senate's 55 to 45 procedural vote Tuesday is not deterring the House from making what they see is a clear case against Trump for his role inciting the insurrectionists. There are still key questions for them to decide before next month's trial: They haven't made a final decision, for instance, on whether they will call witnesses. They're preparing for the possibility they won't have any witnesses -- but they may decide to use them if they find a witness willing to voluntarily step forward, according to sources.
Even without witnesses, Democrats are considering using evidence from video and social media to help illustrate how Trump's words, actions and tweets motivated the rioters to attack the Capitol, the sources say.
The House managers are also preparing to make the constitutional argument -- they're led by Rep. Jamie Raskin of Maryland, a former constitutional law professor -- that the Senate can convict a former President, just as it's held trials for other former officials in the past. It's a case that's taken on newfound importance in the wake of the Senate's vote Tuesday that Sen. Rand Paul forced as part of his argument that most of the Republicans think the trial is unconstitutional -- and there simply aren't 17 Republican votes needed for conviction.
But Senate Democrats say that the case the House managers make can still sway some Republicans, particularly if they can use witnesses who would help corroborate Trump's mindset and actions leading up to the January 6 Capitol riots.
"I think that the core of this case is Trump's incendiary and inciting words, the words out of his own mouth," Connecticut Democratic Sen. Richard Blumenthal told reporters. "But his intent to do harm, to cause injury and maybe even death may come from witnesses who were with him when he was watching the assault on the Capitol. So witnesses can corroborate and powerfully document what we know but they need to prove."
One complicating factor for the House impeachment team is whether potential witnesses would be willing to be called -- particularly those who were in the White House. The House impeachment managers want to avoid any kind of court fight over witnesses like the House had to deal with during the first impeachment of Trump.
Sen. Angus King, the Maine independent who caucuses with Democrats, said Tuesday it was an open question whether executive privilege would still apply to former White House officials after Trump left office who could be called as potential witnesses. King argued that such testimony could shine light on the President's thinking during the time of the trial.
"It will be either witnesses or documents, and what was given in the way of intelligence," King said.
RELATED: Senate GOP largely votes against holding Trump impeachment trial
The opening day of Trump's second impeachment trial showed just how high the bar is for House Democrats to get anywhere close to the votes needed for conviction, with just five Republicans voting with Democrats to defeat Paul's procedural motion.
While not every Republican who voted with Paul said the trial was unconstitutional outright, the 55 to 45 vote was as clear a sign as any that the path to the 67 votes needed to convict Trump and bar him from running again was all but impossible. Paul claimed after the vote it showed the trial was already over before it started.
Even one of the Republicans who voted with Democrats and is opened to convicting Trump said the writing was on the wall.
"Do the math. I think it's extraordinarily unlikely that the President will be convicted," said Sen. Susan Collins of Maine, one of the five Republicans to break with Paul.
Senate GOP focuses on constitutional argument
Following Tuesday's procedural vote to defeat Paul's point of order that the trial was unconstitutional, the Senate adjourned the impeachment trial until February 9, when arguments will begin.
Senate Republicans have coalesced in recent days around the argument that the trial is not constitutional, giving them a way to push back on House Democrats' impeachment without condoning Trump's conduct when rioters attacked the Capitol on January 6, breaching the very chamber where the impeachment trial will be held.
"I think it showed that impeachment is dead on arrival," Paul said of the vote he forced Tuesday. "If you voted it was unconstitutional, how in the world would you ever vote to convict somebody for this?"
Democrats argued that Republicans were skirting their responsibility to hold Trump accountable for his behavior by claim the trial was unconstitutional. "They don't want to be held accountable on that vote so they're going to try to make it another argument that is all about the Constitution," said Sen. Dick Durbin, an Illinois Democrat.
There were signs ahead of Tuesday's vote that most Senate Republicans would stay united. At their party lunch Tuesday, Senate GOP leaders hosted Jonathan Turley, one of the leading conservative law scholars arguing that the trial is unconstitutional.
While Turley has argued against holding an impeachment trial for a former president, the nonpartisan Congressional Research Service wrote this month that "most scholars who have closely examined the question have concluded that Congress has authority to extend the impeachment process to officials who are no longer in office."
Alaska GOP Sen. Lisa Murkowski, who has said Trump committed impeachable offenses and voted against Paul on Tuesday, expressed frustration with the vote that occurred before the trial even started -- and with less than a day's notice.
"I think it was a little unfortunate that we had this very spontaneous vote on an extraordinarily significant matter without the considered debate and analysis. People had to make really quick decisions," Murkowski told reporters Tuesday. "I'm not saying there's bad faith, but I do think this is significant enough that it deserved greater consideration by this body and I think what you've seen now is people have been forced to take a quick position. Whether or not that changes as we move forward I think remains to be seen."
Sen. Rob Portman, an Ohio Republican, downplayed the significance of Tuesday's vote, saying that he saw it as only a procedural motion and not a statement of whether the trial was constitutional or not.
"I want to hear it debated," Portman said. "I do have questions about the constitutionality, and as a practical matter the precedent, but I want to hear it briefed, and we will hear it."
But Senate GOP leaders remained united with Paul. Senate Minority Leader Mitch McConnell, who has expressed an openness to hearing the impeachment arguments, voted with Paul on Tuesday, in a sign he has questions about the constitutionality of the process. Missouri Sen. Roy Blunt, a member of GOP leadership who is up for reelection in 2022, said following the vote he believes the trial is unconstitutional.
"I believe the constitutional purpose of impeachment is to remove a president from office, not to punish a person after they have left office," Blunt said in a statement. "No consideration was given to impeach President Nixon when he left office in 1974. The Constitution hasn't changed and the Congress should not set a new, destructive precedent."
Several GOP senators have cited the fact that Chief Justice John Roberts will not be presiding over the trial -- with Senate president pro tempore Pat Leahy of Vermont presiding instead -- as the clearest sign that the trial doesn't pass constitutional muster.
"That would send a pretty clear signal to me what Roberts thinks of the whole thing," said Sen. Chuck Grassley, an Iowa Republican.
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