Yuval Levin's claim that the Ryan plan would protect seniors with pre-existing conditions

http://www.nationalreview.com/corner/268378/re-democratic-plan-yuval-lev in Michael F. Cannon, director of health policy studies at the Cato Institute: "All seniors under the chairman's proposal, as I understand it, will be able to obtain health insurance coverage... [payments will be] risk-adjusted so that people with severe illnesses will get larger vouchers." The problems are that (a) the voucher will be too small for the average senior to purchase a policy that offers Medicare benefits, and (b) for many with pre-existing conditions the risk-adjustment will not work--risk adjustment is not an exact science.