An article on how the census screwed up who it counted says:

"Critics say the bureau should have used a complicated statistical method called "sampling" to make up for historic undercounts of minorities. Opponents of that method, mainly Republicans, have said sampling actually inserts more error into a census."

My recollection wasn't that republicans thought that you shouldn't sample cause it would give the wrong answer, but rather because the constitution says to count and sampling isn't counting...