What you don’t seem to get is that a majority of the country sees impeachment as a fundamentally illegitimate attempt to overturn the result of the election of 2016.
There are no high crimes and misdemeanors. The Mueller report does not say what you want it to say. He did not indict Trump for Collusion after the Resistance Democrats have been screaming for two years that he would. In fact he found there was insufficient evidence to indict any American of criminal conspiracy with Russians in connection with the election. There went the vaunted Collusion Conspiracy theory.
Most people are sick of hearing about this and have had enough of these partisan investigations. Most do not want to be educated by Pelosi or anyone else.
The case against Nixon grew stronger over time. The revelations made the Watergate story more interesting. In contrast the case against Trump has grown weaker. The release of the Mueller report has convinced a large segment of the public that impeachment is not warranted. There was no collusion. No criminal investigation was actually obstructed. Mueller did not even recommend making charges of obstruction after Trump left office.
By making impeachment the central issue of the 2020 campaign, you will motivate lots of people to come to the polls to let you know they have had it with your refusal to accept the results of 2016. This will hand Trump a victory and return all the moderate House seats back to Republican hands. That’s why Trump is goading Nancy to impeach him.