Humphrey won 18 % of write - in votes in the Massachusetts primary ; it was seen as a victory over Kennedy 's 28 % vote total .
Kennedy 's Massachusetts campaign organization was significantly stronger than Humphrey 's .
Humphrey won 18 % of write - in votes in the Massachusetts primary ; it was seen as a victory over Kennedy 's 28 % vote total because Kennedy 's Massachusetts campaign organization was significantly stronger than Humphrey 's .