House impeachment managers and President Donald Trump's defense team faced questions from senators on Wednesday as Trump's Senate trial entered a new phase.

The first query, from the three GOP senators who are most likely to vote to continue the trial with additional witnesses, may well have been the most pivotal. Senators remained divided over the issue Wednesday, with Republicans working get the vote need to block a call for witnesses.

Here's a look at some of the best — and most important — moments from Wednesday's question and answer session.

Read more here.

Here's how the trial stands after tonight's revelations about Collins, Alexander, and others.

It’s looking highly likely that there are not 51 votes for additional witnesses.

TOMORROW:

1 P.M.: Trial resumes

• Up to four hours of debate (equally divided) on the witnesses and documents question.
• A vote on the motion of whether begin deliberations and votes on witnesses and documents.
• If that fails, then a number of different motions are in order.
• The trial could wrap up by the end of the day Friday.

DES MOINES, Iowa — While the Senate debated his removal from office, President Donald Trump jabbed at his Democratic opponents here as some campaigned to replace him just miles away.

Trump focused most of his attacks on former Vice President Joe Biden and Sen. Bernie Sanders, I-Vt. — both leading the Democratic presidential pack — while expressing disbelief at his impeachment trial back home.

"We are having probably the best years that we have ever had in the history of our country. And I just got impeached. Can you believe these people? I got impeached. They impeached Trump," he said. "No, that's not gonna work. Watch. Just watch."

More here.

Sen. Lamar Alexander, R-Tenn., revealed late Thursday that he plans to vote against hearing from witnesses during the Senate trial. 

“The question then is not whether the president did it, but whether the United States Senate or the American people should decide what to do about what he did," Alexander, who is retiring this year, said in a statement on Thursday. "I believe that the Constitution provides that the people should make that decision in the presidential election that begins in Iowa on Monday."

Sen. Susan Collins, R-Maine, meanwhile, said Thursday that she will vote in favor of hearing from witnesses during the Senate trial. 

“I believe hearing from certain witnesses would give each side the opportunity to more fully and fairly make their case, resolve any ambiguities, and provide additional clarity. Therefore, I will vote in support of the motion to allow witnesses and documents to be subpoenaed,” she said. 

Collins, who is running for re-election this year, said that if the motion passes, she believes the most sensible way to proceed “would be for the House Managers and the President’s attorneys to attempt to agree on a limited and equal number of witnesses for each side. If they can’t agree, then the Senate could choose the number of witnesses.”

Sen. Mitt Romney, R-Utah, has made it clear that he plans to vote in favor of witnesses. Sen. Lisa Murkowski, R-Alaska, said she will review her notes and then decide. Democrats need four Republicans to vote with them in order for the trial to advance to a witness stage. 

Collins makes it official: she's supporting calling witnesses.

"I believe hearing from certain witnesses would give each side the opportunity to more fully and fairly make their case, resolve any ambiguities, and provide additional clarity," she said in a statement.

Democrats need at least three other Republican votes to be able to pass a resolution allowing for new witnesses and documentary evidence. The fate of the resolution, which is expected to be taken up Friday, remains uncertain.

Sen. Lisa Murkowski, R-Alaska, a key swing vote on whether to call witnesses in the Senate trial, said after the conclusion of the question-and-answer period that she's going to review what she's heard and then decide whether she needs to "hear more." 

“I am going to go reflect on what I have heard, re-read my notes and decide whether I need to hear more," she said. 

Trump's trial has adjourned for the day, ending hours of questions — 180 in total, according to an NBC News count — from the senators and leaving one big one still unanswered: Will Democrats be successful in their push to call additional witnesses?

Here are the key moments from Thursday, which marked the conclusion of the question-and-answer portion of the Senate trial. Sen. Lamar Alexander, R-Tenn., a key impeachment swing vote, plans to reveal later tonight whether he supports calling witnesses. 

The trial will resume at 1 p.m. Friday.

Three GOP senators asked the president's defense if Congress has other means for “consequential responses” to a president's conduct other than impeachment — especially in an election year. 

In response, Philbin said that Congress can put pressure on the executive branch by not funding the president’s policy priorities or cutting funding; not passing legislation that the president favors or passing legislation that the president opposes or holding up presidential nominees in the Senate.

“They all should be used, they all should be exercised in an incremental fashion,” said Philbin, who also said, “impeachment is the very last resort.” 

Rep. Adam Schiff, D-Calif., the lead House manager, said, “And what's the remedy that my colleagues representing the president say that you have to that abuse? Well, you can hold up a nominee.”

“That seems wholly out of scale with the magnitude of the problem,” he said. “That process of appropriations or nominations is not sufficient for a chief executive officer of the United States, who will betray the national security for his own personal interest.”