Doing nothing will.

Congressional hearings and kick his ass on Nov 3, 2020.

Now he's talking about a third term:

Now he's just doing it openly.

THEY NEED TO DO WHAT IS RIGHT, RIGHT FUCKING NOW

Do an inquiry.

Get the facts. Stack them up one on the other.

Inform the Republicans of the facts. Dare them to dispute the facts. Double dare them.

Then impeach.

Trump easily can be impeached by the House, no problem. But he will be found Not Guilty in his Senate trial, there just aren’t 20 Republican Senators who would throw him under the bus to get to the required 67 guilty votes. That means Trump would have more than a year for voters who are at all inclined to vote for him to forget about impeachment before he runs for reelection.
My personal preference is to keep Trump under constant congressional investigation, including an on-going impeachment inquiry so that he doesn’t have a single day between now and election day when he isn’t on the defensive. Impeachment, a trial and a not guilty verdict lets him off the hook.

exonerated. Once the Senate moves not to convict, Repubs will all call “closed” and that, in the eyes of too much of the public, will be it. Any further investigation or hearing or discussion will be labeled sour grapes.
We need to keep him under a cloud. Candidates under a cloud are at a disadvantage.

His unrelenting quest to impugn HRC with every crime ever committed (hyperbole) and his ceaseless going after her makes him as responsible for the traitor being in office as anyone. His hatred of her was visceral and vicious.

they need a fail-safe strategy with no room for error. They can't give Republicans any opening to take over the show.

They impeached Clinton in 1998 with 29% of Americans favoring impeachment. The Senate didn't convict. The GOP "won" the presidency in 2000.. not really, but you know what happened.

impeachment followed by a failure of the Senate to convict.

A failure by the Senate to convict after impeachment by the House will cast shade on the GOP Senators looking for re-election in 2020.

Not stop Trump from having an exoneration parade as he is going into the General.

That's pure bullshit.

I'm already seeing people saying "They have no case, that's why they are not impeaching"

I am fighting THIS war. And in THIS war with THIS President, I think impeachment is a bad idea at THIS time. Because the President does not care if he is impeached. He knows the Senate will never convict. He will scream and holler and make a fuss and act like he doesn't like. But that's exactly what he does want. Precisely because it gives him the negative attention he wants. It allows him to dominate the news, because impeachment is all about him. Like a naughty child, he wants the negative attention. He acts upset but secretly he is laughing. So it is no deterrent. Instead it shows Congress' impotence because they can't convict.

And that is what Pelosi is doing. She is exercising her judgement. She is definitely not saying "This is what happened before, therefore it will happen again." That's not judgement. Judgement is your best estimate of what will or won't work under current conditions. The past may offer clues, but it does not control the present, or offer a hard and fast rule. She judges that impeachment will not have the desired effect. I concur.