WASHINGTON - Wisconsin Republican Ron Johnson joined all but two of his GOP colleagues Friday in rejecting a call to hear witnesses in President Donald Trump's impeachment trial.

Every Senate Democrat, including Wisconsin's Tammy Baldwin, voted for witnesses. They were joined in that vote by Republicans Susan Collins of Maine and Mitt Romney of Utah.

The motion for witnesses failed 49-51.

Both Johnson and Baldwin made it clear in advance how they would vote on the question.

“My bottom line is: This impeachment trial has got to end, the sooner the better. Witnesses are just going to prolong it without really giving us any more information than we really need,” Johnson told Wisconsin listeners to a telephone town hall he held Thursday.

After one caller asked him, “How do you reconcile not calling witnesses in this impeachment when every other impeachment has had witnesses?” Johnson replied that calling former national security adviser John Bolton as a witness would “drag this thing out a long time” due to White House opposition and “lengthy litigation” over executive privilege.

“I don’t know what he’s exactly going to say, but … I can’t imagine he’s going to provide any kind of bombshell revelation on this,” Johnson said of Bolton, who has reportedly written a book manuscript that says the president sought to freeze military aid to Ukraine until that country investigated Democrats, including former Vice President Joe Biden and his son.

Trump and his defense team have denied that.

“I’ve called on John Bolton to just come forward and tell us what you know. You don’t have to subject yourself to a subpoena and that kind of litigation,” Johnson said during the telephone town hall. “Now, he can’t reveal classified material, but based on the fact that there is a book out there that’s being leaked, I’ve told John just come forward and let us know. I don’t think it’s going to affect it one way or the other.”

Johnson said, “I think we basically know the facts” and said the Democratic-led House “has made a mountain out of a molehill.”

Baldwin released a video message Thursday saying:

“Today we are in the same place we started. We don’t have what we need for a full, fair and honest trial — critical documents and relevant witnesses with firsthand knowledge about the President’s conduct. Every Senate impeachment trial in our nation’s history has included witnesses and this Senate trial should be no different.”

Baldwin said reports about Bolton’s book manuscript make it clear that Bolton has information that would “go to the heart of this impeachment trial: abuse of power and obstruction of Congress.”

Said Baldwin: “It is my hope my Republican friends in the Senate would want to have John Bolton testify under oath, so we can have all the facts. The American people just want the truth.”

At a news conference with Democratic colleagues Monday, Baldwin said Bolton's accounts suggest the president didn't tell the truth to Johnson last summer. Johnson has said Trump denied to him that he was withholding aid to Ukraine to pressure that country to investigate Democrats.

"It is my hope that my Republican friends would want to know if there is evidence that the president did not tell one of my colleagues the truth. The people of Wisconsin certainly want to know if the president did not tell Sen. Johnson the truth," Baldwin said.