Will Wilkinson plays devil's advocate and argues against birthright citizenship. Abolishing it is unlikely to happen - it would require a constitutional amendment - but the EU's immigration experiment is still worth highlighting:
The EU’s shortcomings, from bureaucratic micromanagement to a floundering common currency, have obscured its great practical and moral triumph: the dramatic expansion of European mobility rights and the inspiring integration of the continent's labor markets. When Britain opened its labor markets to Polish workers in 2004, the gap in average income between the two countries was about as big as that between the United States and Mexico. But per capita GDP in Poland has improved markedly since then, hastening the day when Poland provides a robust market for British goods and possibly British labor, too. Similarly, by 2012, Romanians and Bulgarians, who are on average poorer than Mexicans, will be able to live and work in rich countries such as France, Germany, and Britain. It’s worth noting, however, that not a single EU country has a birthright citizenship rule like that in the U.S.
My guess is many Americans would have less of an objection to the presence of Mexican immigrants, authorized or unauthorized, on American soil if that presence did not tend to create so many new citizens and thereby so many new claims. Right-wingers constantly say they wouldn’t mind higher levels of immigration if it wasn’t for the welfare state. Some of these people are just rationalizing their xenophobia, but I think most of them mean it. I’m just taking the logic of that claim seriously, and I think the experience of other countries shows that there’s something to it.