A Few Thoughts on Impeachment and the 2020 Democratic Ticket

1. OK, impeachment is probably unstoppable at this point. The question is time frame. The House and Senate will both "slow-walk" or "fast-track" proceedings based on factors they believe help them more or hurt them less next November.
2. My guess is that the House will fast-track, because Joe Biden is done. The more quickly that's made clear and the more quickly he drops out, the less damage to the eventual Democratic ticket. He's a scab that has to be torn off in time for the wound to heal over some. And the Republicans are only going to turn up the volume of their "but your guy did it too, and first" howling when impeachment gets real.
3. My guess is that the Senate will slow-walk because their nomination is a coronation and they think having Trump in the dock toward the peak of the Democrats' primary race (or heck, even as late as their national convention) will benefit him, not them.
4. It will take more than what's already out there to shame the Republican Senate into convicting. It may not be possible for that to happen under any circumstances. Then again, it may.

Up to now, my (very tentative) prediction for the Democratic nomination has been "Biden, or Warren, or a Biden/Warren ticket."

Now that (still tentative, but less so than before) prediction is "Warren."

Running mate? Probably male. Probably midwestern or southern. Probably a person of color. Buttigieg and Booker each punch two of those categories on the scorecard; Castro hits on all three. But it could be someone who isn't even running for president.