Chris Wallace suggests that the news of Bolton's book had the potential to change how the president's impeachment trial proceeds.
No one should doubt Bolton's attention to detail—and his appetite for bureaucratic score-keeping.
Just two GOP senators were exceptions—Mitt Romney and Susan Collins—both of whom signaled before the Bolton revelations they'll side with Democrats to subpoena witnesses and documents.
"It's pretty fair to say that John Bolton has a relevant testimony to provide," the Republican senator told reporters.
"To support Ukraine is to support a rules-based international order that enabled major powers in Europe to avoid war for seven decades," William Taylor wrote.
Obama-era appointee Joyce Vance said a tweet denying the claims wasn't "enough" as Bolton was willing to testify.
"The Democrat controlled House never even asked John Bolton to testify. It is up to them, not up to the Senate!" Trump tweeted on Monday.
The ex-national security advisor has reportedly written a book claiming he had a conversation with President Donald Trump about withholding aid over the Biden investigations.
Joseph Bondy tweeted that it was "curious" that Bolton was reportedly told of "the same Presidential quid pro quo" his client has described.
A book by President Donald Trump's former National Security Advisor John Bolton reportedly includes details of alleged conversations about withholding military aid to Ukraine.
Bolton reportedly said Trump told him he wanted to continue withholding military aid to Ukraine until its officials agreed to help probe his Democratic rivals.
The likelihood of such a potential deal seems miniscule, as many Republicans have said they don't believe any witnesses are necessary and Democrats say Hunter Biden is irrelevant to hear from.
"I think we ought to go through the right process," the lawmaker from Florida said.
The president also said it would not be good to have someone testify who had left his administration on bad terms.
The Washington Post reported that the Trump administration is considering blocking possible public testimony from former National Security Advisor John Bolton on national security grounds.
"I think they [the Senate] should hear the testimony that they can get," Congressman Francis Rooney said.
"That directly contradicts what you said as a Republican House impeachment manager in 1999 during the Clinton impeachment trial," Chris Wallace noted.
Republicans for the Rule of Law will begin running advertisements during Fox News programming calling for the testimony of John Bolton during the impeachment trial.
Most GOP senators believe the deal with Ukraine the president tried to make was "improper" but not impeachable, the Fox News analyst said.
"Next to Donald Trump himself, this could be the most important witness that the Senate could call to determine what the actual facts are," a former Watergate prosecutor said.
The poll by Quinnipiac University also found just under four in 10 Republicans wanted the former national security adviser to appear before lawmakers at the trial.
The former GOP presidential nominee suggested he would vote in favor of hearing testimony from the former national security adviser.
Texas Rep. Dan Crenshaw also asked why House Democrats did not subpoena President Donald Trump's former national security adviser during the impeachment inquiry.
Andrew Napolitano cited "new emails of people getting instructions directly from the president to hold up on the sending of the [military] funds [to Ukraine]."
The former national security adviser is believed to have firsthand knowledge of the president's Ukraine dealings and his decision to withhold $400 million in military aid from the U.S. ally.
"We have ZERO problems with the American people...Our sole problem is Trump. In the event of war, it is he who will bear full responsibility," a top Iranian presidential adviser said on Twitter.
"Staying silent will only lead observers to infer that you care more about book royalties than, you know, who should be the president of the United States," Daniel W. Drezner wrote.
"Forgive me for being snarky and blunt, but he's stealing a page from Omarosa's playbook," Mark Groombrdige told CNN.
Bolton, whom Trump ousted from the position in September, wrote in a tweet that more "effective" policy would be needed to keep the United States and its allies safe from North Korea.
The former national security advisor said he does not think North Korea will ever voluntarily surrender its nuclear weapons, regardless of what Kim Jong Un tells Trump.