ABC News chief legal analyst Dan Abrams shot down speculation that former national security adviser John Bolton would soon be testifying.

Despite debate about whether or not Bolton would take part in the Senate impeachment trial of President Donald Trump, Abrams was adamant that it is “not happening” as there are too many levels to get through to make it possible.

(Video: ABC News)

“I have concluded that, if the Senate issues a subpoena for my testimony, I am prepared to testify,” Bolton said in a statement earlier this month, setting off Democrats who have been gleefully anticipating the prospect of hearing from the man who served for more than a year until his departure in September.

But Abrams threw cold water on the idea during special coverage on ABC News following the swearing-in of senators for the start of the impeachment trial. Congressional reporter Mary Bruce noted that there are “at least four Republicans who have said they are at least interested in hearing potentially from additional witnesses.”

“Much of the power is in the hands of these key Republican senators when it comes to whether or not we will hear any new testimony or hear any new evidence being considered. And Democrats are very hopeful that they can sway these Republicans,” she said.

Anchor George Stephanopoulos brought up Bolton’s name again before Abrams interjected.

“John Bolton’s not testifying in front of the Senate,” he said.

“Positive?” Stephanopoulos asked.

“It’s not happening. It is not happening,” Abrams reiterated. “He’s a very smart guy. He knows how the process works. He didn’t say ‘I’ll volunteer.’ He said ‘if subpoenaed.’ So when people say he’s offered to testify? What do you mean? He’s agreed to abide by a subpoena.”

Even if the key GOP senators crossed party lines to join Democrats in calling for Bolton’s testimony, Abrams noted that the process would get tangled and ultimately result in Bolton not appearing before the Senate.

“Let’s assume that they get the 51 votes and they say, ‘We want John Bolton to testify,’” Abrams said. “He shows up, and then there’s going to be an argument on immunity. And there’s going to be an argument on executive privilege. And the president is going to say, ‘It is my executive privilege here. It is not his decision.’ And it’s going to work its way through the courts. And they’re going to say, ‘We don’t have the time.’ And John Bolton’s not testifying.”

“I think Bolton could still testify,” law professor Kate Shaw said after Stephanopoulos asked if she thought Supreme Court Chief Justice John Roberts, who is presiding over the Senate trial, would need to rule on the issue.

“I think there could be assertions of privilege,” the ABC News contributor said.

“And then I think the Chief would be in a very difficult position to just say, ‘Senators, you work it out. Or let’s let the court process run its course.’ I think there would be a strong argument that the comparative advantage of ruling on this important Constitutional question about the privilege,” Shaw added. “The way the president’s communications with his advisors are subject to disclosure, and where, and how, that’s a legal and Constitutional question that the Chief Justice is better situated to answer than the members of the Senate.”

“But the Chief Justice doesn’t want to answer that question,” Abrams argued. “And as a result, he won’t!”

“I think he may feel that it looks too political to try to avoid answering the question,” Shaw replied.

Sens. Susan Collins and Lisa Murkowski have pushed back on the calling of witnesses like Bolton.

“It’s clearly not the right time for us to judge which specific witnesses should be called,” Collins told reporters on Wednesday.

“Am I curious about what Ambassador Bolton would have to say? Yes, I am,” Murkowski told Alaska Public Radio in an interview on Monday.