canvasser

nouns

a petitioner who solicits contributions or trade or votes
canvasser, solicitor
is derived from
canvas
someone who examines votes at an election
canvasser, scrutineer
someone who conducts surveys of public opinion
"a pollster conducts public opinion polls"; "a headcounter counts heads"
canvasser, headcounter, poll taker, pollster
is derived from
canvas
is derived from
canvass
a person who takes or counts votes
canvasser
is a type of (narrower)
an official appointed to count the votes (especially in legislative assembly)
teller, vote counter