WASHINGTON D.C. - The impeachment trial of President Donald Trump continues on the Senate floor on Saturday morning.

President Donald Trump's lawyers opened his impeachment defense in a rare Saturday trial session.

They say the Democrats' investigation into Trump's dealings with Ukraine was not a fact-finding mission but rather a politically motivated effort to drive him from the White House.

The arguments were aimed at rebutting allegations that Trump abused his power when he asked Ukraine to investigate political rival Joe Biden and then obstructed Congress as it tried to investigate. The defense is asserting an expansive view of presidential powers and portraying Trump as besieged by political opponents.

On Friday evening, House impeachment managers concluded their arguments as to why they believe senators should convict and remove President Trump from office. They focused on the obstruction of Congress. Democrats who took the floor argued Trump blocked their investigation into his activities regarding Ukraine.

"President Trump tried to cheat," said Rep. Hakeem Jeffries (D- New York). "He got caught, and then he worked hard to cover it up."

In order for the Senate to call on witnesses during its impeachment trial, at least four republicans will have to vote with the democrats for it. However, many in the Senate republican majority appear to be unconvinced. 

"I'm trying to do my job to be impartial," said Sen. Rick Scott (R- Florida), "I'm listening to both sides. I think the House managers have done a poor job."

Democrats in the Senate have said they want to hear real counter arguments from the President's attorneys now. They will begin their defense of Trump on Saturday morning, and will continue next week.