The sentence has two major errors (which when spoken seems correct, but when written has a different meaning). firstly, let's see what the correct sentence should be - "it isn't fair that people judge others by their mistakes".

In a modern democracy all elected officials serve for a certain number of terms then must retire a high school sophomore and a senior citizen may vote at the polls together a united states senator votes on immigration law on behalf of your mother through indirect ballot all democracies have a two chamber system of representation united states citizens live in a direct democracy