And yet the foreign leader felt no pressure even as the American left was yelling "Feel some pressure, damn you!". Here's pressure: "I leave on a plane in a few hours and if that prosecutor isn't fired, you're not getting the money." Clearly, Biden and Obama show us that pressuring a foreign leader in regard to aid is perfectly fine, but still Trump didn't take that tact. What you described is asking for an investigation. There is no "If the president is named Trump and a person desirous of the office is named Biden" constitutional exclusion to equal justice.
I don't need Alexander to interpret either instance; I can read and think for myself. In Lamar's opinion,
“It was inappropriate for the president to ask a foreign leader to investigate his political opponent and to withhold United States aid to encourage that investigation. When elected officials inappropriately interfere with such investigations, it undermines the principle of equal justice under the law. But the Constitution does not give the Senate the power to remove the president from office and ban him from this year’s ballot simply for actions that are inappropriate."
And Lamar was in the minority of Republican Senators. He was in the overwhelming majority when stating:
“The Senate has spent nine long days considering this ‘mountain’ of evidence, the arguments of the House managers and the president’s lawyers, their answers to senators’ questions and the House record. Even if the House charges were true, they do not meet the Constitution’s ‘treason, bribery, or other high crimes and misdemeanors’ standard for an impeachable offense.
“The framers believed that there should never, ever be a partisan impeachment. That is why the Constitution requires a 2/3 vote of the Senate for conviction. Yet not one House Republican voted for these articles. If this shallow, hurried and wholly partisan impeachment were to succeed, it would rip the country apart, pouring gasoline on the fire of cultural divisions that already exist. It would create the weapon of perpetual impeachment to be used against future presidents whenever the House of Representatives is of a different political party.
“Our founding documents provide for duly elected presidents who serve with ‘the consent of the governed,’ not at the pleasure of the United States Congress. Let the people decide.”
While I've seen Democrats tout your snippet of Alexander's statement; they remove his tongue before and after it.