Actually, Trump has called out the Bidens for what is completely "undefendable" and that's what has gotten him into trouble.
Let me ask you......
1) Was it "defendable" for Adam Schiff to claim that his panel had not spoken to the whistleblower when everyone knew they had? Even the viscerally anti-Trump Washington Post gave him 4 Pinocchios for that claim.
https://thehill.com/homenews/media/...ives-schiff-four-pinocchios-for-whistleblower
2) Was it "defendable" for Schiff to deny all of the Republican witness requests during the Intel Committee hearings?
3) Was it "defendable" for Adam Schiff to subpoena and then spy on the phone records of Trump's lawyer, Nunes, and John Solomon?
4) Was it "defendable" for Schiff to not even show up yesterday at the Judiciary Committee hearings to defend his own report?
5) Was it "defendable" for Nadler to not even allow for a minority hearing of the Judiciary Committee before drafting Articles of Impeachment, as required by the committee rules?
Please, go ahead and justify all of that. You have it all backwards.
And, btw, Trump is 100% right about the Bidens and Ukraine, and in time that will be definitively shown - just as the IG report yesterday showed that the dossier was pure nonsense (which is what Trump and others maintained all along). Nunes in his 2018 memo was absolutely right. At the time he was mocked but it turned out that he was the one who was right.