The case is a good example of why popular reporting about how the Supreme Court works often misses the mark. The case really isn't about patent trolls--the policy question of balancing patent rights versus other consideration is squarely in Congress's wheelhouse. Instead, this is a dispute about what Congress has already said. Specifically, what it has said about "venue" in patent cases.

"Venue" is the idea that several courts may have the power to hear a case (i.e. they have jurisdiction over the case and over the defendant), but that for various reasons we may want to funnel the litigation to particular courts. Venue rules are set forth in federal law.

28 U.S.C. 1400(b) states: "Any civil action for patent infringement may be brought in the judicial district where the defendant resides, or where the defendant has committed acts of infringement and has a regular and established place of business." That's a venue provision specific to patent cases. It tends to limit where venue is proper (i.e. where lawsuits can be brought), because ordinarily "residency" for a corporation is defined pretty narrowly.

There is also a more general venue provision, 28 U.S.C. 1391(a)-(c), which provides for venue in, among other places, wherever a corporate defendant is subject to personal jurisdiction. That tends to permit venue in more places, because corporations can be subject to personal jurisdiction almost everywhere they have a substantial business presence (under the theory that if you do business somewhere, you can't complain about being taken to court there).

The Supreme Court held in 1957, in Fourco Glass v. Transmirra Products, that in patent cases, only section 1400 applies, not the more general venue provision in section 1391. That is, until the Federal Circuit determined that subsequent amendments to section 1391 had the effect of making the more general venue provision of section 1391 applicable to patent cases too.

Now, whatever you think of patent trolls, you kind of have to handicap the case in favor of Kraft (the party arguing for broader venue). The text of the current version of section 1391 is pretty clear: an action may be filed in "a judicial district in which any defendant resides," where the "residency" of corporate defendants is defined as "any judicial district in which such defendant is subject to the court’s personal jurisdiction with respect to the civil action in question," for "all venue purposes."

Kraft argued at the Supreme Court the definition of "residency" in 1391(c) applies "for all venue purposes," including for purposes of section 1400. Thus, even if section 1400 is the exclusive venue provision in patent cases, it incorporate's 1391(c)'s broad definition of where a corporate defendant "resides."

Undoubtedly, many pages will be spent arguing about the effect of one reading of the statutory text versus the other vis-à-vis patent trolls. Some justices will care about that, because they view statutory interpretation through the lens of policy decisions. Others will not care. Not because they do or do not like patent trolls, but because to them statutory interpretation is a matter of what the words on the page say, not policymaking.