The presence of the top officials is the latest sign that Arizona will play a prominent role in the immigration debate as President Barack Obama looks to make it a signature issue of his second term.
Napolitano toured the border near Nogales with the highest-ranking official at U.S. Customs and Border Protection, the incoming chairman of the Senate's homeland security committee and an Arizona congressman. Napolitano, Arizona's former governor, said afterward that comprehensive immigration reform will strengthen the nation's border against criminals and other threats.
Also Tuesday, McCain hosted two town hall meetings in Arizona, during which he defended his immigration plan to upset residents concerned about border security. A bipartisan group of senators—including Arizona Republicans McCain and Jeff Flake—want assurances on border security as Congress weighs what could be the biggest changes to immigration law in nearly 30 years. Arizona is the only state with both of its senators working on immigration reform in Congress, a sign of the state's widely debated border security issues.
Immigration activists and elected officials say it's only natural for Arizona to continue to take the forefront in the national conversation on immigration after years of internal debate on the topic.
"No state in this country has had more experience with enforcement-only immigration laws than Arizona," said Todd Landfried, executive director of Arizona Employers for Immigration Reform, which opposes the state's tough immigration laws.
During a heated town hall gathering in the Phoenix suburb of Sun Lakes, McCain said the border near Yuma is largely secure, but he said smugglers are using the border near Tucson to pump drugs into Phoenix. He said immigration reform should be contingent on better border security that must rely largely on technology able to detect border crossings.
McCain said a tamper-proof Social Security card would help combat identity fraud, and noted any path to citizenship must require immigrants to learn English, cover back taxes and pay fines for breaking immigration laws.
"There are 11 million people living here illegally," he said. "We are not going to get enough buses to deport them."
Some audience members shouted out their disapproval.
One man yelled that only guns would discourage illegal immigration. Another man complained that illegal immigrants should never be able to become citizens or vote. A third man said illegal immigrants were illiterate invaders who wanted free government benefits.
McCain urged compassion. "We are a Judeo-Christian nation," he said. McCain's other town hall meeting took place in Green Valley, south of Tucson.
Arizona gained international recognition as an epicenter of the U.S. immigration debate when it passed its tough anti-immigrant law in 2010. A handful of other states—including Georgia, Indiana, South Carolina and Utah—have since adopted variations of Arizona's law.
Arizona has the nation's eighth-highest population of illegal immigrants, according to the Pew Research Hispanic Center. In 2010, illegal immigrants represented roughly 6 percent of the state's population.
Activists said Arizona's anti-immigrant laws inspired many illegal immigrants to demand more rights. Last week, some college students rallied outside Arizona Gov. Jan Brewer's office for driver's licenses for illegal immigrants.
"They no longer are afraid to come and say, 'I am not able to vote, but I can make my voice heard, and they have to listen to me,'" said community organizer Abril Gallardo.
A report released in January showed the U.S. Border Patrol's Tucson sector remains the busiest along the U.S.-Mexico border. The Tucson sector accounted for 38 percent of all drug seizures and 37 percent of all apprehensions along the border.
Brewer said last week the border cannot be declared safe until the people living near it feel secure from drug and human trafficking.
But Democratic Congresswoman Kyrsten Sinema of Arizona told Latino and black community leaders at a Phoenix luncheon Tuesday that Arizonans need to spread the word on how much more secure the border has become.
"There are lots of folks who don't live in Arizona who have no idea what the border is like," Sinema said.
Napolitano toured the border Tuesday afternoon with U.S. Customs and Border Protection Deputy Commissioner David Aguilar, Democratic Rep. Ron Barber of Arizona and Democratic Sen. Tom Carper of Delaware. Carper is the incoming chairman of the Homeland Security and Governmental Affairs Committee.
She said in a statement after the tour that border crossings are down 50 percent since 2008 and 78 percent since their peak in 2000.
Cristina Silva can be reached at http://www.twitter.com/cristymsilva.