I agree with you about the ACA (as an opponent of single-payer). Prior to the ACA, members of my immediate family were uninsurable on the individual market --- not insurable at a higher rate, not insurable with exclusions, but literally uninsurable: their only options were employer-provided group coverage or state catastrophic safety net coverage programs. The twist: neither has any chronic health conditions. The underwriting refusals were based on symptoms reported in previous engagements with the health care system.