The Supreme Court today rejected federal preemption of a drug case on a 6-3 vote.

There are several surprises here. First, the margin: 6-3. With Justice Clarence Thomas concurring! What’s unusual about that is that Justice Thomas usually votes with Justice Antonin Scalia. In this case, Wyeth v. Levine, Justice Thomas not only went his own way, but the dissent wasn’t even written by Justice Scalia as many people expected: instead, it was written by Justice Samuel Alito. Chief Justice John Roberts rounded out the minority.

Second surprise: that the majority went anti-preemption at all. After the court last year split 4-4 on another drug preemption case (with Chief Justice Roberts recusing because of stock ownership), and after it voted 5-4 to preempt most medical device cases, many — again — expected this conservative-leaning court to vote for preemption, even if by the narrowest of margins. A 6-3 vote sounds more convincing than 5-4.

Third surprise: although the FDA’s 2006 preemption rule — the Preamble to the Final Rule — was de-emphasized as Levine briefing progressed, the majority seemed to blast it amidships. Will it take on water and sink in lower court rulings yet to come?

A side note: some, including me, had wondered if Chief Justice Roberts would recuse himself from Levine because, after arguments, Pfizer announced a deal to buy Wyeth. The chief justice had owned stock in Pfizer, which is what kept him out of the 4-4 drug preemption vote. We may never know what happened in Levine; did he sell the stock or reason that his stock ownership had too remote a bearing on his participation?

Right now, I’m sure the plaintiffs bar is popping champagne corks: the ruling gives life to pending drug litigation. Indeed, many cases were on hold for Levine, so the floodgates will open. One of the big questions is: will the ruling result in new filings? Drug complaints have been down over the past year. Some of that is due to a dearth of drugs-gone-bad, but plaintiff attorneys tell me they had one eye on Levine in deciding whether to start new litigation. Besides, there’s so much economy related litigation to go after!

Another big question is whether there will be a new drug preemption challenge. Like most Supreme Court decisions, the court today appears to have allowed some wiggle room, so might drug companies come back and try to carve out exceptions? That could be their only option: many of the pro-preemption rulings have come from judges appointed by the business-friendly, tort-reform-minded former administration and from agency rules. Now, there’s a new administration and the FDA might not as inclined to carry water for tort reform.

Finally, with a Democratic Congress, it’s unlikely that there will be any legislation to regulate drug litigation one way or the other. In fact, Levine may have influence on medical device litigation: after the Supreme Court last year tightened up litigation for devices, the old Congress introduced a bill to overturn it. Now, not having to fight a battle over drug litigation, the device bill may be revived.