"The President, Vice President and all Civil Officers of the United States, shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors."
United States Constitution, Article II, Section 4.
The law on "Bribery of public officials and witnesses" in the U.S. Criminal Code reads. . .
"Whoever. . . being a public official or person selected to be a public official, directly or indirectly, corruptly demands, seeks, receives, accepts, or agrees to receive or accept anything of value personally or for any other person or entity, in return for. . . being influenced in the performance of any official act. . . shall be fined under this title or not more than three times the monetary equivalent of the thing of value, whichever is greater, or imprisoned for not more than fifteen years, or both, and may be disqualified from holding any office of honor, trust, or profit under the United States."
Title 18, United States Code, Section 201(b)(emphasis mine).
This is the main charge against Trump. Other charges are likely to include obstruction of justice and obstruction of Congress.
Here is how impeachment works. . .
"The House of Representatives shall chuse their Speaker and other Officers; and shall have the sole Power of Impeachment."
United States Constitution, Article I, Section 2, clause 5.
Upon being impeached by the House of Representatives, the President is tried by the Senate.
"The Senate shall have the sole Power to try all Impeachments. When sitting for that Purpose, they shall be on Oath or Affirmation. When the President of the United States is tried, the Chief Justice shall preside: And no Person shall be convicted without the Concurrence of two thirds of the Members present."
United States Constitution, Article I, Section 3, clause 6.
Impeachment and trial are done by the rules of the respective chambers. There is no requirement for "due process of law," because the Constitution states that
"No person shall. . . be deprived of life, liberty, or property, without due process of law. . ."
United States Constitution, Amendment V.
But the Constitution is clear that an official impeached and tried can suffer only removal from office, and not deprivation of life, liberty, or property. . .
"Judgment in Cases of Impeachment shall not extend further than to removal from Office, and disqualification to hold and enjoy any Office of honor, Trust or Profit under the United States..."
United States Constitution, Article I, Section 3, clause 7.
So there you have it. This guide should help people cut through the torrent of bullshit from Trump and his supporters whimpering about "quid pro quo" and "due process" and all that other TV-programme lawyering.