Why does the government want to know how many toilets you have in your home?

It might seem like a silly question, but it is now central to a dispute between congressional Republicans and the Obama administration over the kinds of questions that the Census Bureau can ask in its mandatory surveys.

In addition to the decennial census, the government’s head-counters every year send 3.5 million Americans a lengthy questionnaire seeking a wide range of information about their living situation and employment status. Known as the American Community Survey, it replaced the “long form” portion of the official census beginning a decade ago. In addition to questions about the number of toilets, since 2010 the ACS has also asked about what kind of plumbing people have in their homes, and about their Internet access, energy use, whether they receive food stamps, if they live over a store, and how many cars they drive.