The Senate doesn't even have to take it up. The Constitution grants the Senate the sole power to try an impeachment case. There's no constitutional mandate that they do so. It's actually the same language as that giving the house the sole power to impeach. Since there's no mandate that the House exercise its power to pass articles of impeachment, there's similarly no mandate for the Senate to exercise its power to try the case.
If they do take it up, they could also literally immediately vote to dismiss all of the charges without even holding a trial.
Now I don't think they'll do that. They'll use their chance to control the process to hold the same kind of circus the Dems have been holding for no other reason than PR.
I also disagree that it will be a constitutional crisis if he's reelected after this. Lord knows we've had plenty of worse situations in the past. A President using official power to try to advance his own career is hardly a blip on the radar considering the true horrors committed by Presidents before him.
I honestly consider the bigger threat to be a failed use of the impeachment power. I think too many on the left are letting their hatred of Trump blind them to the realities of the situation. Impeaching Trump and failing to remove him from office does little except undermine the legitimacy of the threat of impeachment, stirs up Trump's base making them more angry and so more likely to vote, deepens the divisivness that already consumes US politics, and emboldens Trump in the future.
Impeaching him without knowing he's likely going to be removed from office would be nothing but a release of frustration by the left that would do more harm than good. Pelosi has been well aware of this fact which is probably why she opposed impeachment for so long.
