The next president will inherit a broken immigration system.

With the number of illegal immigrants in the United States estimated at more than 12 million, he will remain under public pressure to take bold steps to deal with the issue. President Bush tried but failed in that effort when Congress did not pass comprehensive immigration reform that he supported.

Nowhere is the issue more pressing than in Arizona. The state's portion of the U.S.-Mexican border remains the main gateway for illegal border crossings, which has led to about 1,000 migrant deaths here since 2003.

Arizona also is a major destination for new immigrants, both legal and illegal. This state is home to an estimated 500,000 undocumented immigrants, making up 9 percent of the state's population, the highest portion of any state, according to the Pew Hispanic Center, a research organization.

After immigration reform collapsed in Congress, Arizona and many other states have passed their own laws to grapple with the issue. ...