http://docs.law.gwu.edu/facweb/jsiegel/publications/waivers.pdf
The limits on this sovereign immunity include:
(1) The “good faith” of the states, that they will not refuse to honor “obligations imposed by the Constitution and by federal statutes that comport with the constitutional design.” Id. at 755.
(2) Claims for which the states have consented to suit. Id. at 755.
(3) Claims against states by other states or the federal government. Id. at 755.
(4) Suits in which immunity is abrogated pursuant to Congress’ 14th Amendment authority. Id. at 756.
(5) Suits against local government entities. Id. at 756. See § 4 below.
(6) Ex parte Young claims. Id. at 756-757. See § 3(a)(iii)(1) below.
(7) Individual capacity claims against state officials. Id. at 757. See § 3(b)(i) below.
(8)Possibly, situations in which states manipulate their immunity in a systematic fashion to discriminate against federal causes of action. Compare Alden, supra, 527 U.S. at 758. See also § 8(b) below.
Accordingly, although
private parties may not use damage actions to enforce federal law
against states, the federal government may itself enforce federal
law—apparently including federal law that regulates the behavior of
states toward private parties—by bringing actions for monetary relief
against states that violate federal law.
