From From Johnson v. Advance America, 2008 U.S. App. LEXIS 25050 (4th Cir. Dec. 12, 2008):

Advance America contends that the minimal diversity requirement is satisfied in this case. It argues first that because Advance America is incorporated under the laws of Delaware and is therefore a Delaware citizen, its citizenship is different from the citizenship of the class members. Although Advance America is also a citizen of South Carolina, where it has its principal place of business, it asserts that its "dual citizenship in South Carolina does not destroy the minimal diversity created by certain alleged South Carolina citizens suing a Delaware corporation." Stated otherwise, it maintains that "Advance America's dual citizenship is sufficient to establish minimal diversity under CAFA," regardless of the citizenship of the plaintiffs.

Advance America is correct in noting that it, as a corporation, has dual citizenship for purposes of determining diversity jurisdiction. "[A] corporation shall be deemed to be a citizen of any State by which it has been incorporated and of the State where it has its principal place of business." 28 U.S.C. § 1332(c)(1) (emphasis added). The statute's use of the conjunctive gives dual, not alternative, citizenship to a corporation whose principal place of business is in a State different from the State where it is incorporated. Therefore, for purposes of diversity jurisdiction, Advance America is a citizen of both Delaware, its State of corporation, and South Carolina, the State of its principal place of business. Yet, Advance America relies on its Delaware citizenship to create minimal diversity, ignoring the fact that it is also a citizen of South Carolina. Whether it is entitled to rely on only one citizenship where its other citizenship would destroy federal jurisdiction is resolved by the statutory language itself and by the burden of proof imposed on removing parties.

As noted, the burden of establishing diversity jurisdiction remains with Advance America. Thus, to establish minimal diversity under CAFA, Advance America must demonstrate that "any member of [the] class of plaintiffs is a citizen of a State different from any defendant." 28 U.S.C. § 1332(d)(2)(A) (emphasis added). It cannot, however, demonstrate that the plaintiffs, who are South Carolina citizens, are citizens of a State different from Advance America. This is because Advance America is a citizen of South Carolina, even though it is also a citizen of Delaware. Because Advance America has South Carolina citizenship, it cannot carry its burden of demonstrating that the citizenship of the South Carolina class members is different from its own. The language of the statute imposes a requirement on Advance America to prove the negative -- i.e. that it is not a citizen of South Carolina -- and that it cannot do. Accordingly, we reject its argument that its dual citizenship entitles it to rely on its Delaware citizenship to establish minimal diversity under CAFA.