TWO CHEERS FOR THE ALL-POWERFUL STATE. Some may disagree, but I say liberals should probably celebrate today's ruling that the Employment Retirement Income Security Act (ERISA) supersedes the Maryland law forcing Wal-Mart to pay into a health fund. ERISA allows for uniformity across a single company's nationwide benefit plans so employers don't have to face down new regulations in every state. The Wal-Mart bill, according to the court, violated that legislative intent. By contrast, the judge wrote that something like the Massachusetts reforms do not, because they were an example of "states [performing] their traditional role of serving as laboratories for experiment in controlling the costs and increasing the quality of health care for all citizens," and were not, in intent, clear violations of ERISA.

So why should liberals rejoice? Well, though a piece of friendly legislation was knocked down, the active principle behind the court's ruling is a supportable one. If states were able to invalidate federal health care statutes, any sort of truly universal or comprehensive reforms would crash on the shoals of a thousand commerce clause challenges. The eventual aim is to smooth the disjointed patchwork of state, local, and private care systems and replace it with something more standardized, navigable, and comprehensive. For that to be possible, the federal government needs to retain its authority to trump state legislation. If the Maryland bill -- which was neither a good bill nor particularly important -- is our only casualty in that fight, liberals will have gotten off easy. The only real downside here is that this sort of legislation will no longer be available as a cudgel against Wal-Mart.

--Ezra Klein