Arizona Border Dispute

Actress Laura Bell Bundy attends the 61st Annual Tony Awards at Radio City Music Hall on June 10, 2007 in New York.
Getty Images/Peter Kramer
By Bryan Sanders of the CBS News Political Unit.

Republican Sens. John McCain and Jon Kyl of Arizona recently introduced competing immigration reform bills, highlighting yet another GOP split on an issue President Bush has made a priority for his second term.

McCain's legislation, the Secure America and Orderly Immigration Act, is co-sponsored by liberal Democrat Ted Kennedy of Massachusetts, making it a bipartisan alternative to Kyl's bill, which is co-sponsored by Texas Republican John Cornyn, but has yet to gain support from any Senate Democrats.

Immigration reform is expected to rise to the top of the legislative agenda when Congress returns in September, due in part to the declining momentum for Social Security reform, but also because a state of emergency on the U.S.-Mexico border was declared last week by the governors of New Mexico and Arizona.

There is emerging consensus at the state and national level that the U.S. immigration system is broken and needs to be fixed. On both sides of the aisle, legislators identify enhancing border security as a key component of homeland security, made urgent by the threat of Islamist terrorists taking advantage of weak enforcement on America's borders.

In terms of enforcement, the Kyl-Cornyn and McCain-Kennedy bills are similar. Each addresses border security using a variety of methods, including new technologies, broader cooperation and increased manpower.

Where the competing proposals diverge is on two more contentious issues: a guest worker program and the status of illegal aliens already living in the United States.

A guest worker program is the centerpiece of Mr. Bush's immigration reform agenda, and the competing bills both call for establishing one. The idea of such a program is to allow foreign workers to apply for temporary visas to come to America and work low-skill jobs American citizens do not want.

But the Arizona Republicans are at odds over the length of stay for the guest workers, and whether these workers will ultimately be permitted to apply for green cards before they return home.