Two veterans of the Supreme Court bar argued forcefully — and inconclusively — Wednesday in a high-stakes dispute over how easy it should be for a patent holder to win an injunction against an infringer.

From the tenor of the questioning in eBay v. MercExchange, justices seemed closely divided over the issue, alternately sympathetic toward Sidley Austin’s Carter Phillips, arguing his 49th case at the Court, and then toward his adversary, WilmerHale’s Seth Waxman, appearing before the high court for the 47th time.