Based on my own experience as a Census worker, I wouldn't be surprised if one or two million people (or more) tried to boycott the Census this year. I say "tried" deliberately, because I don't know of a single instance where someone who refused to cooperate with the Census was not counted. We used other sources, including postal workers, town offices, employers, neighbors, and relatives to acquire the necessary (and very limited) information. So even if JW tried to boycott the Census, it's unlikely they would have been more than slightly successful from the Census's viewpoint.