Congress has gathered and presented its information to the Senate. The Senate’s job is to now determine if the Congress’s information meets the criteria for Trump to be impeached based on what Congress has presented to them … and nothing else.
It is not the Senate’s job to call witnesses to either confirm or disprove Congress’s case, only to judge it. Now four Republican senators (RINOs) want to call in witnesses to help do Congress’s job?
Congress wants the president impeached because they disagree with his political policies since day one of Trump’s presidency. This, plus innuendo, rumors and "I believe" are not grounds to impeach any sitting president. This is outside the bounds of the Constitution.
What’s worse is that four senators now want to go against the established rules of the Constitution by calling in witnesses. If both the Congress and Senate work outside the limits of our laws, the Constitution, then America has an illegitimate government.