Texas Gov. Rick Perry has cast himself as the true conservative among Republican presidential candidates, but his record on immigration could tell a different tale.

Perry consistently invokes the need to secure the border when talking about immigration, and the phrase does a good job of illustrating his platform. He has distinguished between tightening enforcement along the border and how the government treats undocumented immigrants already inside the country.

On the latter he has shown himself to be considerably more moderate than the rest of the party, at times appearing closer to Democratic positions.

In 2001, Perry signed a law making undocumented students who graduated from Texas high school eligible for in-state tuition at public universities. Democrats in California's state legislature are advancing a similar bill over the loud protestations of Republicans, and Democratic Gov. Edmund G. Jerry Brown has promised to sign it.

He also criticized Arizona's controversial immigration enforcement law, breaking with Republican governors across the country who backed legislation with tough enforcement measures similar to those imposed by the Arizona law. Critics of those laws have argued that they end up deporting too many nonviolent offenders, often sweeping up people who have committed minor civil offenses.

Perry has faulted Arizona by admonishing that our focus must continue to be on the criminal elements involved with conducting criminal acts, implicitly advancing the same argument as immigration advocates and progressives.

Central to Perry's conservative credentials is his embrace of the autonomy granted to states through the 10th Amendment to the U.S. Constitution. That has allowed him to tout Texas' fiscal health and criticize measures, like the health care overhaul, that extend the reach of the federal government.

It has likely informed his immigration policies as well: Texas contains an estimated 1.6 million undocumented immigrants in addition to a substantial Latino electorate, so alienating immigrants wouldn't necessarily be a shrewd political move.

Perry's opponents have spotted the opening. Speaking at the National Hispanic Assembly, Mitt Romney offered a critique of the in-state tuition bill without directly mentioning his rival.

We must stop providing incentives that promote illegal immigration, Romney said. As governor, I vetoed legislation that would have provided in-state tuition rates to illegal immigrants.