Byron York

Then there is taxpayer-subsidized, in-state tuition for illegal immigrants. Perry signed the Texas Dream Act in 2001 making it the law in Texas. "We must say to every Texas child learning in a Texas classroom, 'We don't care where you came from, but where you are going,'" Perry said at the time. "The message is simple: Educacion es el futuro, y si se puede." Perry still supports the measure.

Finally, there is the question of guest workers. "I support a guest worker program that takes undocumented workers off the black market and legitimizes their economic contributions without providing them citizenship status," Perry said in 2006. "A guest worker program that provides foreign workers with an ID removes the incentive for millions of people to illegally enter our country." To critics, that's just amnesty with a different label.

Perry does oppose sanctuary cities, but on the other hand, he has been critical of the new Arizona immigration law, which has widespread support in the Republican base.

Immigration was a red-hot issue among Republican voters in 2007 and 2008. It almost killed the candidacy of Sen. John McCain, who had to retreat from his advocacy of comprehensive immigration reform and take up an enforcement-first position. Now, it could be that, given the breadth and depth of today's economic worries, immigration is a less important issue among Republicans. But reports from the campaign trail suggest it comes up a lot in the candidates' question-and-answer sessions, and voters mostly want to hear tough positions that are the opposite of Perry's.

A challenge on immigration is in the offing for Perry. How he handles it could determine the success or failure of his candidacy.

Byron York

Byron York, chief political correspondent for The Washington Examiner