Frankly, I thought the question of overpopulation and all it's Malthus-obsessed prophets of doom had been satisfied by Mr. Swift's classic treatise on the matter, but it seems many in the U.S. are still concerned with the matter. More importantly, they (like so many) are reveling in blaming the immigrants (at least according to this slick new campaign).
But perhaps (say it ain't so!) their ire is misplaced. There's a right-quick way to tamp down population growth (which, were one to do so, it would only serve to exacerbate the growing fiscal crisis that is medicare, medicaid, and social security) and raise more tax revenue for the shit-storm it would create (see last parenthetical note):
Stop subsidizing children.
Why should families get paid $3500 to have a kid? Once the cost of child ownership goes up, people will be less inclined to have them (or so the strictures of neo-liberal economics would insist), and production will decline. It's just like corn and gasoline.
In any case, illegal immigrants come into the country at prime working age, unsubsidized, often pay into social benefits without ever receiving them, and in many ways prop up the country without taking very much besides a chance for a better life from it. Plus they constitute an essential part of our national ethos (unless we choose to abandon it before they can get here).
Happy Tax Day, Everyone!