If Marsha Blackburn gets the hearings she’s called for on the Census Bureau (I wouldn’t hold my breath), one of the things they need to address is whether the White House plans to halt immigration enforcement so as not to scare off illegal aliens during the count. That’s what Carter did in 1980, the goal being to create more Democratic seats in the House (and in the state legislatures), the same way the slaveholders at the Constitutional Convention had wanted slaves counted as full persons, so slave states would get more representation in Congress (without the slaves, of course, having a say in who those representatives were). Here is our estimate of how seats were shifted among states as a result of counting illegals in the 2000 census. If you pushed the lefties, their preferred response, of course, would be to rectify the mismatch between illegals (and legal non-citizens) being counted but not voting by giving non-citizens the vote (see here and here). Instead, it would seem the best way to resolve the issue of illegals in the census (since you can’t expect people to check off that they’re illegal) would be to step up immigration enforcement in the lead-up to the enumeration so as to scare off the illegals and ensure that fewer of them get counted.