How many representatives does each state get in the House of Representatives? The Constitution (technically the 14th Amendment) says:
Representatives shall be apportioned among the several States
according to their respective numbers, counting the whole number of persons in
each State, excluding Indians not taxed.
That is pesky for Senator Vitter. Louisiana stands to lose a seat in the House if illegal aliens are counted in the 2010 census because they don't have a lot of illegal immigrants. By comparison, states like Texas and California have many illegal aliens and will gain seats in the House.
So what is Senator Vitter to do? Prevent illegal aliens from participating in the census by forcing the census workers to ask about immigration status. He didn't come out and say that on the floor of the Senate. Instead, he offered this fig leaf, "we would have no opportunity to debate [the 14th Amendment apportionment] or to adopt a new
plan unless the census distinguishes between citizens and legals and illegals, which my amendment would demand we do."
As an added bonus, he is throwing this amendment in now, after the Census Bureau has already printed and distributed the census forms. Unforunately for Sen. Vitter, his amendment has little chance of passing.