Eight houses with "Vote No" signs on their lawns were vandalized Monday night, police said.
According to a report by KARE 11, vandals spray-painted the yard signs and a few garage doors with depictions of male and female genitals.
KMSP-TV reported that victims got out early to scrub the garage doors. Some took the day off to paint over the vandalization.
Signs were defaced, victims said.
They had to roll up the garage doors Monday morning so children walking to their bus stops wouldn't be exposed to the lewd images.
Blaine police were on scene Tuesday morning to gather evidence in an attempt to find those responsible.
They will face bias crime charges, police said.