John Daniel Davidson of the Federalist argues Democrats seem to have ignored valuable lessons from past presidential impeachment probes.

The history of impeachment proceedings in the modern era, from Nixon to Clinton to Trump, shows that a successful impeachment needs three things: it must be bipartisan, it must be about something Americans think is important, and Congress must strike while the iron is hot. In Trump’s case, Democrats have botched all three.

First, this impeachment inquiry is an entirely partisan affair. The public hearings of recent weeks have made this undeniable, but even before the hearings it was obvious that Democrats alone were going to conduct this impeachment. The House’s impeachment inquiry resolution passed last month without a single Republican vote, and in fact two Democrats joined GOP lawmakers in voting against the resolution, making opposition to the impeachment probe bipartisan. …

… Second, Democrats have failed to make their case against Trump compelling because they’ve turned it into a process story tailored for the media, not the American people. Cable news and mainstream outlets feed off the drip-drip-drip of lengthy impeachment hearings and hours of tedious testimony, but the public is decidedly less interested.

In fact, impeachment is having the opposite effect Democrats hoped it would, according to a series of recent polls that show support for impeachment has been dropping since the public hearings began. …

… Third, House Democrats have missed their window for a politically advantageous impeachment vote. If they were going to do it, they should have done it as soon as Trump released the transcript of his July 25 call with Ukrainian President Volodymyr Zelensky back in September. Pelosi should have instructed House Judiciary Committee Chairman Jerry Nadler to ram through articles of impeachment and then immediately hold an impeachment vote.