Observers are allowed in a designated space, behind a guard rail, at least six feet from voters, poll workers, and marking shelves.
However, any engagement, disruption, or intimidation of voters is illegal. Observers shall only observe quietly from behind the guard rail. If observers are deemed in any way disruptive by Election Officials, they will be asked to leave the polling location. The Town Clerk may ask for the assistance of law enforcement if desired.
For more detailed information, see the Massachusetts Attorney General’s Advisory on the subject: https://www.mass.gov/news/ag-healey-issues-advisory-on-poll-monitoring-and-voter-intimidation
Or view Chapter 54 of Massachusetts General Law: https://malegislature.gov/laws/generallaws/parti/titleviii/chapter54; Sections 25 and 69 in particular.