So, we along with them know it's going to fail. So why are they insistent on having it?

They're going to use it as a leverage to drop their sham unity act. They will then use their whole "you're enemies of democracy" and jam down the most insane of agendas. This may be the catalyst for the Supreme Court packing.. They know its going to fail, but they'll insist "you guys could've had unity if you supported convicting Trump". This in my opinion is the only reason they've gone through with it, going so far as wiping their asses with the constitution so brazenly as they have with it, from getting another judge other than Roberts, and going through with it nonetheless. They have been pushing the idea of "convicting Trump" because when it fails, they're going to go into full on attack mode. We'll see legislation and laws passed to attack us, I truly believe it. We may even see them calling on left wing vigilantes to attack while celebrities and other figures support attacking us and "deprogramming". They're not about unity and justice, they're about continuing their fight to make sure that an outsider like Donald Trump never comes in again to help the people they fuck over to line their pockets. It's a sad state of affairs that we live in. It truly is. But who knows, this is just a prediction.