In case you’re interested, here’s the legal brief the House impeachment managers filed today.
The president’s legal team published a response (not a legal filing), which you can read here:
Based on first impressions, I’d say the House brief looks indefensible. The very first sentence of the introduction states: “President Donald J. Trump used his official powers to pressure a foreign government to interfere in a United States election for his personal political gain, and then attempted to cover up his scheme by obstructing Congress’s investigation into his misconduct.”
I don’t doubt that President Trump “used his official powers to pressure a foreign government” to do something the President wanted. But I have yet to see evidence the President wanted a foreign government “to interfere in a United States election,” whether to the President’s “personal political gain” or for any other reason.
To be blunt about it, show me the President saying in writing or in front of witnesses, “I want Ukraine to interfere in the 2020 election.” If you can’t do that, then the President’s defense team is correct: “The Articles of Impeachment are constitutionally invalid on their face.”