Similar to the House-passed bill (the American Health Care Act), the Cassidy-Graham bill would provide states expansive waiver authority to eliminate or weaken the prohibition against insurance companies charging higher premiums based on their health status and the requirement that insurers cover the essential health benefits related to any health insurance plan that is in any way subsidized by the bill’s block grant funding. States seeking waivers would only have to explain how they intend to maintain access to coverage for people with pre-existing conditions, but they wouldn’t have to prove that their waivers would actually do so. 
The success of a policy can be measured by changes in the behavior of the target population and active support from various actors and institutions involved. A public policy is an authoritative communication prescribing an unambiguous course of action for specified individuals or groups in certain situations. There must be an authority or leader charged with the implementation and monitoring of the policy with a sound social theory underlying the program and the target group. Evaluations can help estimate what effects will be produced by program objectives/alternatives. However, claims of causality can only be made with randomized control trials in which the policy change is applied to one group and not applied to a control group and individuals are randomly assigned to these groups.