Mass. Gen. Laws ch. 53 § 76
Notices of caucuses shall apply to all members of the party calling them, and to them only. No person having voted in the caucus of one political party shall be entitled to vote or take part in the caucus of another political party within the twelve ensuing months; except that voting or taking part in the caucuses of any municipal party by any voter shall not affect his legal right to vote or to take part in the caucuses of any political party, for any other election, and having voted or taken part in the caucuses of a political party for any previous election, shall not affect his right to vote or take part in the caucuses of any municipal party, nor shall a voter who is enrolled under section thirty-seven or thirty-eight as a member of a political party be entitled to vote in the caucus of another political party held in a city while so enrolled. No voter, not hereinbefore disqualified, shall be prevented from voting or participating in any caucus if he takes the following oath, which shall be administered to him by the presiding officer of the caucus:
You do solemnly swear (or affirm) that you are a registered voter in this ward (or town) and have the legal right to vote in this caucus; that you are a member of the political party holding the same, and intend to vote for its candidates at the polls at the election next ensuing; and that you have not taken part or voted in the caucus of any other political party for twelve months last past.
Such voter may be challenged like any other voter. Any person whose right to vote is challenged for any cause recognized by law shall not be permitted to vote until he has taken the foregoing oath; and the clerk or secretary of the caucus shall make a record of the administration of said oath to every person taking the same, which record shall state whether or not said person voted. The record shall be returned with the proceedings of said caucus and shall be prima facie evidence in any court that such person took said oath and voted in said caucus.
A caucus officer or a voter violating any provision of this section shall be punished by a fine of not more than five hundred dollars or by imprisonment for not more than six months.
Mass. Gen. Laws ch. 53, § 76