28 U.S.C. 1441. Actions removable generally

• (a) When District court has Original Jurisdiction....
• (b) ...action is removable regardless of citizenship of parties.
• (b) Otherwise, only if Defendants are not citizens of the State.
• (c) When otherwise non-removable claim is joined to removable one.
• (d) When Defendant is a foreign state.
• (e) District court will have jurisdiction, even if state court didn't.

• (a) Except as otherwise expressly provided by Act of Congress, any civil action brought in a State court of which the district courts of the United States have original jurisdiction, may be removed by the defendant or the defendants, to the district court of the United States for the district and division embracing the place where such action is pending. For purposes of removal under this chapter, the citizenship of defendants sued under fictitious names shall be disregarded.
• (b) Any civil action of which the district courts have original jurisdiction founded on a claim or right arising under the Constitution, treaties or laws of the United States shall be removable without regard to the citizenship or residence of the parties.
• Any other such action shall be removable only if none of the parties in interest properly joined and served as defendants is a citizen of the State in which such action is brought.
• (c) Whenever a separate and independent claim or cause of action within the jurisdiction conferred by section 1331 of this title is joined with one or more otherwise non-removable claims or causes of action, the entire case may be removed and the district court may determine all issues therein, or, in its discretion, may remand all matters in which State law predominates.
• (d) Any civil action brought in a State court against a foreign state as defined in section 1603(a) of this title may be removed by the foreign state to the district court of the United States for the district and division embracing the place where such action is pending. Upon removal the action shall be tried by the court without jury. Where removal is based upon this subsection, the time limitations of section 1446(b) of this chapter may be enlarged at any time for cause shown.
• (e) The court to which such civil action is removed is not precluded from hearing and determining any claim in such civil action because the State court from which such civil action is removed did not have jurisdiction over that claim.