For those of you who don't understand the game, here it is:
Pelosi has the numbers to pass articles of impeachment. McConnell has the numbers to ensure Trump is not convicted in that impeachment trial.
It would take the defection of 20 Republican Senators to convict Trump in an impeachment trial. Trump currently has a 90% approval rating among Republican voters. Voting to impeach would piss off those voters and ensure that Senator loses re-election. Nixon did not resign until his approval rating among Republican voters was around 60%. That won't happen to Trump during the Fox News era.
So, if Nancy impeaches, Mitch the bytch will "exonerate" Trump, and from that day until Election Day, all you're going to hear from the GOP, Republican pundits, Republican Voters, and trolls is "Trump was cleared of all charges/innocent/Russia Hoax."
We are 17 months out from Election Day.
That means we are in the middle of the large Democratic field, as the party's platform is built from an amalgamation of the best ideas of our 20-odd candidates. Right now we need primetime debates, and the primetime media coverage is being fought over fiercely by each of the candidates. Dems need every second of good press they can get.
Trump, on the other hand, is doing barely any campaigning. It's still more campaigning than any other President would be doing, but he's still out there very little in comparison. He's fundraising for the real election season next year, mostly. And planning.
Politically, there are four benefits to an impeachment trial with a guaranteed failure. First, it motivates the base to see their opponent on trial. Second, all of that overwhelming evidence demotivates the centrists aligned with the party on trial. They won't necessarily switch parties, but they're more likely to not vote. Third, it absolutely drowns out all other news coverage. Nobody else will be able to breathe in that media ecosystem without addressing it. And fourth, whoever is on trial in the Senate is nearly-grounded to DC. They won't be out heavily campaigning, they'll be reliant on surrogates for grip-and-grins.
Now, effects 1 and 2 only remain active so long as the trial continues. Once it's over and the trolls get to chant "Russia Hoax" the spell is broken and the motivation leaves an exasperated base and rejuvenated opposition.
Effect 3 is the exact opposite of what the Dems need right now. That kind of media blackout will drown campaigns who can't get their message out, and so can't get funding. You'll see a boost in the Senator-candidates campaigning like Harris, but campaigns like Buttigieg will die a lonely death out in the cold. The simplest solution to this is have the media circus after we have chosen a candidate and pushed our message out to the people. If the people know what we stand for, we'll survive the storm more intact.
The fourth effect would be useless right now when Trump is barely campaigning. But it would be incredibly next August-September-October. Imagine a candidate who could barely leave DC, who couldn't go out to see their supporters. It'd be doubly effective on Trump, who thrives off his cult-like rallies.
Lastly, House Democrats get to decide how long the impeachment trial lasts.
So if Pelosi times this right by holding off on impeachment for one year, we could ground and destabilize Trump's 2020 campaign, while mobilizing our own voters, and pushing the Senate vote back until after the election, so that the decision on whether Trump stays President or not is made in the ballot box instead, and we never have to hear "but he was found innocent" once this cycle.
OR
She could impeach right now and we get "bUt HE waS eXoNeRaTeD" for a year straight.