Here's the response I received from my Senator...
Dear Mr. BassNBrew,
............
I have been clear that, based on the unpersuasive evidence collected by the House, and the weakness of their case for impeachment, I do not see the need for additional witnesses. The Constitution provides that the House “shall have the sole Power of Impeachment,” and that the Senate “shall have the sole Power to try all Impeachments.” It is the responsibility of the House of Representatives during an impeachment inquiry to collect evidence and to make the case for impeachment. It is not the responsibility of the Senate to do the work that the House failed to do, particularly when they failed to issue subpoenas for testimony. This is especially true where the Speaker and the majority have been insistent about the strength of their case justifying the impeachment and removal of a duly-elected President.
As a U.S. Senator, I have a constitutional responsibility to participate fully in the Senate impeachment trial. I will listen to both sides, carefully consider the evidence, and join my colleagues in rendering a verdict. I will also make sure that President Trump is treated fairly and receives a presumption of innocence rather than a presumption of guilt. The President deserves this basic guarantee of due process during the most consequential of constitutional events.