A proposal to base congressional reapportionment only on citizens counted in the 2010 Census would cost California five House seats, an analysis concluded.

Demographers at New York's Queens College said the proposal by Sen. David Vitter, R-La., could reduce the political clout of immigrant-heavy districts, The New York Times reported Wednesday.

"It would mean that regions of states that had fewer immigrants, such as upstate New York, would gain, while those with many immigrants would lose," sociologist Andrew Beveridge, who took part in the analysis, said. "This is going to disempower immigrants massively."

The analysis released Tuesday said New York and Illinois would each lose a seat while Texas, which was projected to gain three seats would only get one new seat. The number of seats in Michigan, Pennsylvania, Iowa and Vitter's state of Louisiana would remain the same rather than be reduced by one each as projected.

The Times said the Constitution requires reapportionment to be based on the Census but 2010 Census form does not ask about citizenship.

Vitter says including non-citizens in the reapportionment count would "artificially inflate the population count" in some areas.