The nation will be watching Tuesday to see whether the U.S. Senate fulfills its constitutional duty by rigorously and objectively examining the allegations against President Donald Trump in his impeachment trial. Republican Sens. Marco Rubio and Rick Scott have an obligation to all Floridians to pursue a full, fair and transparent proceeding complete with witness testimony -- and to sit as open-minded jurors. This is an important moment in America’s history, and Congress’ legitimacy as a co-equal, independent branch of government is on trial as well as the president.

The two articles of impeachment the House appropriately approved last month on partisan votes are straightforward. One alleges Trump abused his office by pressuring Ukraine to investigate a key domestic political opponent while withholding military aid and a White House visit as leverage. The other charges the president obstructed Congress by stonewalling the investigation, defying House subpoenas for documents and blocking testimony from senior aides. There is ample evidence to support both impeachment articles, and it’s up to the Senate to decide whether Trump should be removed from office.

Trump froze $391 million in security aid to Ukraine last summer as White House emissaries pressured Ukraine’s new president to publicly announce his government would launch investigations into the business dealings of Hunter Biden and his father, former Vice President Joe Biden, a leading contender to become the Democratic nominee for president. Current and former senior U.S. government officials recounted how Trump’s personal attorney, former New York City Mayor Rudy Giuliani, coordinated the pressure campaign at the apparent direction of the president.

New revelations over the past week reaffirm the need for witnesses to testify during the Senate trial. A Giuliani associate who played a central role in the Ukraine affair, Lev Parnas, said publicly for the first time that Giuliani assured him the president was fully aware of the pressure campaign. A nonpartisan federal watchdog agency, the Government Accountability Office, said the White House broke the law by withholding the financial assistance to Ukraine that was appropriated by Congress. The Ukrainian government also announced a criminal investigation into reports Trump allies conducted surveillance on the then-U.S. ambassador to Ukraine, whom Giuliani and others had targeted for removal.

The president’s defenders in the Senate dismiss the accounts resulting in the impeachment articles. “This is just them (House Democrats) trying to either get Trump kicked out of office or trying to hurt Trump’s reelection chance,” Scott said in an interview with the Tampa Bay Times. Rubio acknowledged the Senate could call witnesses but insisted the trial be limited to evidence compiled by the House.

Hearing from witnesses whose first-hand accounts the president fought to keep silent is not a new inquiry but the pursuit of a more complete picture. The Senate controls the trial rules of impeachment, and it takes only a majority vote to ensure the fullest airing of the charges.

Senators from both parties are right to push back against measures that would reduce media access to the proceedings. Senators also could stop the video feed from the trial and meet in closed session. Americans deserve to witness this historic trial. All senators must recognize that fact-finding, fundamental fairness and complete openness are essential to ensure public confidence in the institution and in the trial itself -- regardless of the outcome.

Editorials are the institutional voice of the Tampa Bay Times. The members of the Editorial Board are Times Chairman and CEO Paul Tash, Editor of Editorials Tim Nickens, and editorial writers Elizabeth Djinis, John Hill and Jim Verhulst. Follow @TBTimes_Opinion on Twitter for more opinion news