Before Boudin, Ripple,
*fn1 and Selya, Circuit Judges.
In this appeal, the Secretary of State, on behalf of the Commonwealth of Massachusetts, challenges the district court’s determination that Bob Barr and Wayne A. Root, the Libertarian Party’s candidates for president and vice-president in the 2008 general election, were entitled to have their names placed on the statewide ballot even though they had not submitted nomination papers as required by state law. While the particular election that gave rise to this controversy is over, the Secretary also challenges the district court’s related determinations that (i) the Equal Protection Clause of the United States Constitution, U.S. Const. amend. XIV, § 1, affords a right of substitution in the circumstances of this case and (ii) Mass. Gen. Laws ch. 53, § 14, which governs the substitution of certain classes of candidates on the ballot, is unconstitutionally vague as applied to the substitution of non-party candidates for President and Vice-President of the United States.*fn2 Barr, Root, and the other appellees defend the district court’s resolution of these issues and, in doing so, argue that the result reached below was compelled by principles of constitutional law, statutory construction, and estoppel.
After careful consideration, we find that a live dispute remains. With respect to that dispute, we conclude that the Equal Protection Clause does not require the Commonwealth to afford a substitution mechanism applicable to non-party candidates. We further conclude that the relevant statute, while not unconstitutionally vague, is in need of interpretive clarification. Pursuant to principles of Pullman abstention, that interpretation should be effected by the Massachusetts courts. In light of this determination, the appellees’ claims concerning the Secretary’s prior pronouncements (including their estoppel claim) are either moot or likely to be rendered moot by the state courts’ interpretation of the statutory scheme. Accordingly, we reverse in part, vacate in part, and remand for further proceedings consistent with this opinion.
