I seem to recall something happening shortly before that election … something about the stock market, the economy… but it was so long ago… it may have had a wee influence on said election, however.
There’s another example, of course, from those with somewhat longer memories. An actual impeachment of a President occurred waaaaaay back in the last millennium. 1998, I believe. Two years later, the party that impeached him took the White House and retained control of the House. The Senate switched to Democratic control… for two years.
She’s telling the world that he is nuts and that everybody knows it.
As long as the Republicans value the apparatus that is this administration more than they fear the damage Trump can do, impeachment is not a viable option for restraining Trump and is more likely to set him off. It could serve to educate the public.