Lawyers for the president dismissed calls for former Trump national security adviser John Bolton to testify after Trump's legal team concluded their arguments in the Senate.

Democrats have been demanding Republicans call on Bolton after a draft of Bolton's book, in which Bolton reportedly claims Trump told him he was withholding aid to Ukraine until Ukrainians announced an investigation of Joe Biden, was leaked to the media on Sunday night.

"It's not the job of the Senate to do an investigation now that the House did not pursue," a source on Trump's legal team said Tuesday in a background call with reporters, rebuffing calls for an eleventh-hour witness in the trial. "We don't think it's the role of the Senate to start addressing new developments on the fly."

The team had not been briefed on Bolton's manuscript, the source said.

"I don't think anything we've said strengthens the case for witnesses," the source said, and even if the Bolton leak proved true, "it wouldn't make the case for an impeachable offense."

Further, the source said, the House heard testimony from 17 witnesses, including Bolton's deputy, and House managers have stressed how they have overwhelming evidence to move ahead in the impeachment process.

At least one influential Republican senator talked to GOP colleagues about a deal to call two witnesses in the trial. Sen. Pat Toomey of Pennsylvania has proposed a "one-for-one" deal with Senate Democrats in conversation with Sen. Mitt Romney of Utah and others.

Sen. Ted Cruz, who is advising the president's legal team, has suggested hearing from former Vice President Joe Biden and his son Hunter Biden, who sat on the board of the Ukrainian energy company Burisma despite a lack of experience in the energy sector.

Two-thirds of the public polled by the Washington Post and ABC News last week said they believed the Senate should call witnesses in the trial, but they were split along partisan lines. Democrats were in favor of calling witnesses at nearly twice the rate of Republicans, split 87% to 45%. Independents, at 65% in favor, fell between the two.