"The Articles of Impeachment are constitutionally invalid on their face. They fail to allege any crime or violation of law whatever..."

"... let alone 'high Crimes and Misdemeanors,' as required by the Constitution. They are the result of a lawless process that violated basic due process and fundamental fairness. Nothing in these Articles could permit even beginning to consider removing a duly elected President or warrant nullifying the election and subverting the will of the American people."

So reads the second paragraph of the "Answer of President Donald J. Trump" "In Proceedings Before the United States Senate."  My link goes to the PDF at the White House website. I couldn't find a text document of the 6-page letter so there's nothing to cut and paste. The White House website does have this text introduction, which, you can see, stresses the politics:

The Articles of Impeachment submitted by House Democrats are a dangerous attack on the right of the American people to freely choose their President. This is a brazen and unlawful attempt to overturn the results of the 2016 election and interfere with the 2020 election—now just months away. The highly partisan and reckless obsession with impeaching the President began the day he was inaugurated and continues to this day.

Other than the word "he," that sounds like something Trump could say at a rally. It's all about the motivations of the House Democrats, which, I'd like to point out, corresponds exactly to the House Democrats' argument against Trump: He/They took the powers of government and used them for personal advantage and only personal advantage. The legitimate, governmental purpose of that power was completely absent.

If we knew for a FACT that the House Democrats acted solely for their own personal, political advantage AND that Trump acted solely for his own personal, political advantage, do the 2 transgressions cancel each other out? But we don't know these things as facts, and the Democrats are calling on the Senate to answer the question about Trump, but they can't shield themselves from the question about themselves.

I see 3 ways to untangle these parallel problems: 1. The question of the House Democrats' political motivation must be answered first, and if they are appropriating the mechanisms of government solely for political benefit, they must be stopped in the act and denied the use of the Senate, or 2. When there is a legitimate governmental purpose, it's acceptable that a desire for political gain is also present, and that should let the Democrats over the threshold but will also set up the absolution of President Trump, or 3. The political component of impeachment is inherent, open, and part of the constitutional design, entirely different from turning federal spending and foreign policy into a personal, political tool.

But I've been talking about website text introducing the 6-page Answer. In the formal Answer, Trump certainly isn't arguing So what if I'm political too?

The document says he has "not in any way 'abused the powers of the Presidency.'" Everything he did was "perfectly legal, completely appropriate, and taken in furtherance of the national interest." He did "nothing wrong." The call was so perfect that "Mr. Schiff created a fraudulent version" of the call, and that proves the Democrats "knew there was absolutely nothing wrong with that call." As for what they call "obstruction of Congress," the Democrats didn't go to court to resolve the dispute over whether Trump's claim of executive privilege was valid, so they can't turn that into a basis for impeachment.

The Answer concedes nothing. Nothing was personally political. It was all on the highest level. Of course, that's what the House Democrats say about themselves too.