Lawyer Michael van der Veen called impeachment proceedings against the former president a "politically motivated witch hunt" by the Democrats.
Mr Trump is accused of causing riots in the Capitol on 6 January which left five people dead. He denies the charge.
Most Republicans have indicated they will not vote to convict Mr Trump.
The defence team took less than four of its 16 hours, trying to move the impeachment trial to a speedy end.
After this, senators were given four hours to ask questions of the two sides.
