WASHINGTON, D.C., USA — Opening statements in the impeachment trial of President Donald Trump may be done, but the trial itself is far from over, and Maine’s Senators could play a big role in what happens next.

Maine's Independent Sen. Angus King told NEWS CENTER Maine Tuesday he is not sure there will be enough Republican votes to allow John Bolton to testify, despite telling reporters just a day before he believed they did. 

"I can't imagine anyone voting not to after what we heard," King said at his Washington office.

RELATED: Maine on Impeachment: Senators Collins, King face Pres. Trump's trial

He has been outspoken about wanting to see witnesses called in the trial since its start last week. King said he believes hearing from those with direct knowledge could help paint a better picture of the phone call between President Trump and Ukraine, especially the President's former National Security Advisor John Bolton.

A sample of Bolton's book was just released in a NY Times report Monday in which he claimed Pres. Trump told him that he wanted to withhold hundreds of millions of dollars in security aid from Ukraine until its leaders helped investigate the Bidens.

Sen. King said after speaking with a handful of his Republican colleagues Monday night, he is not convinced Bolton will be called but said he remains hopeful.

RELATED: GOP defends Trump as Bolton book adds pressure for witnesses

“I heard a lot of excuses… so maybe they’re going to link arms and it’s not going happen,” King said. “But frankly, I don’t know how you could possibly, with a straight face, say we don’t want to hear from somebody who has direct knowledge of the issue that’s at the heart of the case.”

Now that opening statements are over, King and other senators will have the opportunity to ask both sides questions about the case starting Wednesday.

When asked what he felt should be asked, King referenced a specific question for House Manager and Orlando’s former Chief of police, Democrat Val Demmings.  

“One of the questions she should be asked is ‘how many bad guys would you be able to put in jail if they controlled the evidence that came into the trial?’,” King said. “The whole idea that the President can essentially stonewall the whole process -- provide no documents, no witnesses -- it basically makes the impeachment a dead letter.”

Questions like King's will be submitted have to be submitted in writing.

Maine's Republican Sen. Susan Collins has yet to say definitively whether or not she will vote to allow witnesses, never mind Bolton directly. 

RELATED: Sen. Collins says new Bolton claims 'strengthen the case for witnesses' in Trump's impeachment trial

Collins released a statement Monday saying the report about Bolton's book 'strengthened the case for witnesses' however. 

King would not comment directly on whether or not his colleague should take a tougher stance in the face of mounting pressure from the Republican party. 

"I don't believe Susan Collins reacts to pressure. I think she reacts to what she believes is important to do," King said. "I think she's taking a responsible position."

Senators will return for questioning Wednesday afternoon. The proceedings are scheduled to begin at 1 p.m.