Yeah if it's just the election that Robyn Kennedy was running in (1st Worcester), it's not too crazy.

According to the Sec of State, 14,914 ballots were cast in that race. 350 of 14,914 votes would be about 2.34% of the vote, and according to this site, 18-23 year olds only make up about 6% of the Massachusetts population. Filtering out those that aren't eligible to vote, considering lower turnout rates for primary elections, and then further considering lower turnout rates for younger voters, I think 350 for this district wouldn't be unreasonable.