The Supreme Judicial Court ruled today that people joined under Vermont's old civil-union law first have to dissolve those bonds before they can marry somebody else in Massachusetts.
The ruling comes in a divorce case in which one of the parties discovered the other was still legally a partner with somebody else in a civil union in Vermont. That state has since ditched civil unions in favor of full marriages, but it did not automatically grant people in civil unions an upgrade to marriage status.
The state's highest court ruled a Vermont civil union was the equivalent of a marriage in Massachusetts and therefore falls under state laws against bigamy and polygamy.
Under Massachusetts law, polygamy is against public policy, and there is no good faith exception. Commonwealth v. Mash, 7 Met. 472 (1844) (ignorance of or honest belief about spouse's death no defense to crime of polygamy). The plaintiff has a spouse in Vermont; therefore, his marriage to the defendant was void ab initio [from the beginning] G.L. c. 207, § 8.