"The White House lawyers have adopted an extreme position where public officials can do almost anything for their reelection," said Sen. Richard Blumenthal (D-CT).
Much of the day centered on calls by Democrats for witnesses, and wrangling over the claims of former National Security Adviser John Bolton.
"If we call John Bolton, I promise you, we are calling Hunter Biden," said Sen. Ted Cruz (R-TX) to reporters.
"Let's call John Bolton, let's call Mick Mulvaney," said Rep. Hakeem Jeffries (D-NY), as Democrats turned aside GOP arguments that they never tried to get testimony from Bolton and other White House officials.
"Yes, we should be able to call witnesses, and so should the President," said Rep. Adam Schiff (D-CA), the lead House prosecutor.
"We would expect if they are going to get witnesses, we will get witnesses," the President's personal lawyer Jay Sekulow said on the Senate floor.
Questions from Senators often were softballs lobbed at their side's legal team, allowing them to score points in the arguments over the President's impeachment - or even just to rebut the most recent statement of the other side.
"Would you please respond to the answer just given by the President's Counsel?" Democrats asked at one point.
Under a system also used for the Clinton impeachment trial, Senators submitted their questions to Chief Justice John Roberts - alternating between Republicans and Democrats - and then each side would have five minutes to answer.
It also left the Chief Justice in a somewhat interesting position, as he reads the question, instead of one of the Senate reading clerks.
For example, one question from Sen. Bernie Sanders (I-VT) resulted in the Chief Justice reading a query which said that President Trump had told "thousands of lies."
And there were others.
Eight more hours of questions by Senators are anticipated on Thursday, then the Senate is expected to confront the major question of this trial - will the Senate call witnesses?
If witnesses are voted down, Republicans want to move quickly to a final vote to acquit President Trump.
That could take place as soon as Friday.