Thursday is the final day of questioning in the impeachment trial of U.S. President Donald Trump.
Senators have eight-hours to get answers from the president's lawyers and the opposition Democratic House members who are acting as prosecutors.
A big focus remains unanswered. Will witnesses and new evidence, such as documents and emails be allowed in the trial?
Earlier in the proceedings, Republican Senate Majority Leader Mitch McConnell indicated he did not have the votes to block the Democratic demand for witnesses, but that could change.
Republicans hold a 53-47 majority in the Senate. Democrats need four swing votes to support new evidence and witnesses.
If the door to new evidence doesn't swing open, the two weeklong impeachment proceedings could come to an end as early as Saturday.
Democratic Speaker of the House Nancy Pelosi blasted her Republican colleagues and said without new witnesses the impeachment trial would simply be a sham.
In part, the questioning focused on a broad argument made on Wednesday from Trump defense attorney Alan Dershowitz.
Dershowitz basically said, that anything Trump does in the name of national security, to get himself re-elected is legal, including a quid pro quo deal. Dershowitz say Democrats are taking his words out of context.
Trump's attorneys say the House of Representatives have not proven their case and it is time to move on.
Trump has confidence he will not only be acquitted, but Republican senators will stop witnesses, such as former National Security Advisor John Bolton from testifying.
Trump is on trial, accused of abuse of power and obstruction of Congress. The charges stem from a phone call to Ukrainian President Volodymyr Zelensky.
Trump is accused of asking Ukraine's government to publicly announce it would investigate Former Vice-President Joe Biden, and Biden's son.
Biden could end up running against Trump for president and Trump's accused of trying to embarrass his rival. At the same time, Trump withheld $400 million in military aid to Ukraine.