Unless he receives a presidential pardon, dies, or is so sick he receives sentencing leniency in the form of e.g. house arrest, Rudy Giuliani is eventually going to end up spending some time in Club Fed over this whole Ukraine affair.
The latest House document dump pursuant to the prosecution of US president DonaldTrump in impeachment proceedings is mostly getting noticed for an offered trade: If Trump fires a troublesome ambassador, Ukraine provides dirt on Biden.
Getting less notice is a letter from Giuliani to Ukrainian president Volodymyr Zelensky, requesting a meeting (which apparently didn't end up taking place). And getting even less notice than the letter itself are three references within the letter:
I am private counsel to President Donald J. Trump. To be more precise, I represent him as a private citizen, not as President of the United States. ... In my capacity as personal counsel to President Trump and with his knowledge and consent, I request a meeting with you ...
Whatever Giuliani was up to vis a vis Ukraine, in this letter he openly stated that he was up to it for the personal benefit of Donald Trump, not as part of advancing some supposed "anti-corruption" public policy initiative. And he openly stated that Trump knew what he was up to and approved of it.
He's going under the bus whether Trump personally kicks him there or not.