If you read the transcript of Pres. Trump's conversation with the Ukrainian president, you can see that it pertains to whether Biden had engaged in a quid-pro-quo with Ukraine to shut down an investigation into Hunter Biden and Burisma--something that Biden had bragged about on video (which is also raised in the discussion)--so Biden is going to be the subject of the impeachment proceeding once it reaches the Senate. The issue will not be whether the President made the request, but whether it was proper, which will segue into a more general discussion of equality under the law and whether some animals are more equal than others.
As for the second article, that, too, will turn into a joke because past presidents and their officials repeatedly ignored Congressional subpoenas. As The Economist noted in a May 2019 article, "Donald Trump is not the first president to fight subpoenas." The article notes for instance:
In October 2011 Eric Holder, Barack Obama’s attorney-general, received a congressional subpoena. Mr Obama tried to block it by declaring executive privilege, in June 2012. A court rejected Mr Obama’s blanket claim of privilege, but not until January 2016.(See also "9 Times The Obama Administration Fought Subpoenas or Blocked Officials from Testifying Before Congress"--PJ Media; "Subpoena fight over operation Fast and Furious documents finally settled"--Politico). Trying to distinguish this case because it related to an impeachment investigation will only encourage more impeachment investigations in the future.