“Nothing wrong happened”
The assumption that offering an inducement to the government of Ukraine to cooperate in the investigation of obvious bribery was “something wrong” is a big problem.
The President’s repeated denials of perfectly normal Presidential behavior seems to affirm that IF he did offer a quid pro quo to Ukraine to get them to investigate the Bidens (among other things) that then he did “something wrong”, when he obviously did not.
Not only would that not have been wrong, but there is no evidence for it. There is nothing they have to point to. So they’re liars.