Article 1, Section 2 of the Constitution:
The House of Representatives shall chuse their Speaker and other Officers; and shall have the sole Power of Impeachment.
The Democrats have control of the House (elections have consequences) and the House has the sole power of impeachment.
Pelosi doesn't have to structure the impeachment proceedings based on Clintons, Nixons or Johnsons and the next impeachment doesn't have to be based on Trumps. Even if it's Trump again.
She needs to hold one vote. "Should the president be impeached."
If there ends up being a trial in the Senate do you think Mitch will give in to a single request from the Democrats or base any of his decisions on what happened during Clintons trial unless it benefits him? Of course not and he shouldn't since the people put Republicans in control of the Senate.
The constitution and the law are the only rules that must be followed.
Exactly. There needs to be a vote, a vote of the full house. This is exactly what she is NOT doing because it gives the president rights to subpoena his own witnesses and bring his own evidence. Instead of holding a vote she is engaging in this extralegal partisan display, calling it impeachment, and acting OUTSIDE of the law.