We KNOW why the individual healthcare market is so expensive. We no longer have "uninsurables", the people with an expensive conditions that previously a new insurance policy wouldn't cover. Perhaps they didn't want to pay for insurance, or perhaps they had insurance but it was terminated due to a job loss or the company didn't offer the policy at renewal. These are the people that drive costs up. We know this.  Previously, a person could have gone from "I don't need insurance" to "uninsurable" in a single event.
 To offset those costs you have to have people with minimal current healthcare needs in the same pool. Having a penalty for being uninsured encourages being insured. The premium subsidies encourage being insured.
 This Senate plan still covers those expensive pre-existing conditions. However it makes the penalty for being uninsured $0. It reduces most people's subsidies. We KNOW this will result in a more expensive to insure pool. We KNOW this will make rates go up even more.