Thanks for that response, andyb.
As for whether I think "what Trump did" was improper, I'll start first with Lamar Alexander's statement, which is the bottom line as far as I'm concerned:
Is it "improper" for a President to ask a foreign leader to investigate corruption? If it is, then what is one to make of Biden's brag that, as Vice President, he threatened to hold up U.S. aid (I believe they were loan guarantees) unless the Ukrainians quickly fired a prosecutor that was investigating the company on which his son served on the board? The answer is - it depends. It hasn't been shown, for example, that Biden's action - which on its face amounted to far more of a quid pro quo than anything suggested on the Zelenski call - was intended to benefit his son. Perhaps the firing of that prosecutor coincided with U.S. policy interests without regard to Biden's facially apparent personal conflict of interest. I do know that President Trump was concerned that the Ukrainians were both historically corrupt and had taken sides against him in the 2016 election.
In the end, the bottom line is, whether the call with Zelenski was "improper" or not, the Ukrainians were not aware until weeks later that the aid had been delayed, the Ukrainians themselves did not consider themselves threatened, and the aid was in fact released within the time period that Congress required, without preconditions. I am quite sure this wasn't the first time Trump may have bloviated and ultimately been talked down by his advisors. Just like he tried to order White House counsel McGahn to fire Mueller. The "order" wasn't carried out and Trump ultimately answered all of Mueller's questions.
I salute the many men and women who have, in the face of vilification and character assassination by the partisan press, considered it their patriotic duty to do their best to render sound advice to this "amateur" President. I think the history books will show their counsel was heeded in many circumstances and kept the nation from harm.
I do not consider ,myself a defender of the President (as I've noted before, I voted for Clinton), but I certainly count myself as a lover and defender of the Constitution. Impeachment on such flimsy grounds as that enacted on a party-line basis by the House will come back to haunt the nation. The bar on partisan impeachment envisioned by the Founders has been replaced by the new vision of impeachment as just another weapon in the toolbox of partisan tribalism and warfare.