Lot of misinformation here.
I guess some groups think that advocating suppressing the census count will benefit their bottom line. A state like Montana has a good shot of gaining an additional Representative after the 2020 Census...the last thing we need is people refusing to be counted I'm reasonably confident an additional MT Representative would reflect at least half of my views.. 
@montanajoe Most people don't think of why a census is taken. All state governments re-do drawing their voting district lines due to population changes. Counties must also do this. Every precinct in a county has a population cut off number. If a precinct has grown over that number, a new line must be drawn to keep that precinct within that number. The state government has a federal population number a Federal Representative district number must not go over and a Senate district with a population number it cannot go over. Lines have to be redrawn to keep within that population number. That is where your state could pick up another federal representative or senator if the population growth required another federal voting district to be added.
I worked the census one year. You do not have to answer any personal questions asked on the form. They need to know how many bodies are there and the address of the bodies so lines can be drawn, keeping within the number set for that county voting precinct and those federal districts kept within that set number.
