I explained and justified all the points you brought up. The point of divergence is merely just a convenience. I'm writing this timeline to explore the effects of a different political system in the United States. Yes, I picked the Johnson impeachment as a POD because it's convenient.
Would such a divergence be possible given the change? Yes. Likely? No. The entirety of alternate history, though, is not about the likely. It's about the possible. Things in our timeline happened for a reason, and those reasons are largely deterministic. Frankly, all alternate history is in ASB territority, given your standards.
But I say, once again, this timeline is not about a realistic understanding of what would happen if Johnson was impeached. If it was, I would have titled this thread differently. This timeline is about the difference between a parliamentary political system in the United States vs. the OTL presidential system. I picked a convenient POD and ran with it.
Would such a divergence be possible given the change? Yes. Likely? No. The entirety of alternate history, though, is not about the likely. It's about the possible. Things in our timeline happened for a reason, and those reasons are largely deterministic. Frankly, all alternate history is in ASB territority, given your standards.
But I say, once again, this timeline is not about a realistic understanding of what would happen if Johnson was impeached. If it was, I would have titled this thread differently. This timeline is about the difference between a parliamentary political system in the United States vs. the OTL presidential system. I picked a convenient POD and ran with it.