Defense resumes in key impeachment week; Dems seek witnesses

President Donald Trump's impeachment trial enters a pivotal week as his defense team resumes its case and senators face a critical vote on whether to hear witnesses or proceed directly to a vote that is widely expected to end in his acquittal.

The articles of impeachment charge Trump with abuse of power and obstruction of Congress.

Those decisions on witnesses may be complicated by reports that Trump said he wanted to maintain a freeze on military assistance to Ukraine until it aided political investigations into his Democratic rivals.

That's from former national security adviser John Bolton in a draft of his forthcoming book.

The report by The New York Times was later confirmed by The Associated Press. The revelation challenges the defense offered up by Trump and his attorneys in his impeachment trial.

The Capitol Hill maneuvering will be complemented by high-stakes efforts on both sides of the aisle to claim political advantage from the proceedings as the presidential nominating season kicks off in Iowa on February 3.

After a two-hour opening argument Saturday, Trump's defense team will lay out its case in depth beginning Monday.

White House counsel Pat Cipollone said Trump's lawyers don't expect to take the full 24 hours allotted to them, but there will be arguments from some familiar faces.

Harvard law professor emeritus Alan Dershowitz, former independent counsel Ken Starr and former Florida Attorney General Pam Bondi will speak on specific topics.

Dershowitz said Sunday he would argue that the charges against Trump are too minor to warrant the Republican president's removal from office under the Constitution. Even if true, they did not allege impeachable offenses," Dershowitz told "Fox News Sunday."