In the testimony presented, the impeachment charges have little to do with the phone call, and we already have Trump’s transcript of that. Why would more of that be relevant?
The charges to be tried are that Trump sought to obstruct justice, and that he abused presidential power by instructing his reps to tell a foreign nation that they must help on going public about Joe Biden in order to get the release of vital military aid that Congress had authorized.
GOP defenders in the hearing repeatedly complained that those willing to testify only surmised second hand that this was in fact Trump’s explicit directive, and that none of the team who worked closest to the president and would know full well if this was the policy that Trump himself engineered had testified that it was. Though of course Trump insisted they all refuse to tell what they knew, and they all complied.
Now one of them has said he’ll take an oath to tell the truth on these central questions of fact if the Senate calls him. Do you favor letting those who would know exactly what actually happened testify?