At one point in an Arizona town hall meeting on immigration hosted by Senator John McCain, a 25-year-old woman stood up and begged her senator and others not to call her illegal immigrant and instead use the term undocumented.

Some laughed at her, and one man called out, "I'd like to be called Irish."

It was a moment that epitomized the emotional meeting McCain held in his home state of Arizona, as he works to lower expectations surrounding his plan for immigration reform and hinted at difficult disagreements in Congress.

The raucous exchange illustrated the passion of the debate across the nation as Congress weighs what could be the biggest changes to immigration law in nearly 30 years.

It's not acceptable to have 11 million people living in the shadows of this country. If you believe they are not living in the shadows, I'd like to know what the hell shadows are?

- John McCain, Senator (R-AZ)

Another testy exchange saw a Hispanic businessman complain about being pulled over and asked for proof of citizenship near Tucson. "We are human, we are not slaves," he said. An elderly white woman yelled back, "but you're illegal."

The town hall meeting followed a more one-sided, but equally heated exchange at a town hall in February in suburban Phoenix, where McCain faced down rebukes from a largely older, white crowd opposed to immigration reform.

McCain said the so-called Gang of Eight, a bipartisan group of lawmakers working on immigration legislation in the Senate, has agreed on more work visas for workers and protections for illegal immigrants brought to the country as children, but declined to provide specific details. He cautioned that he was "guardedly optimistic" that Congress would pass reform this year, even as President Barack Obama renewed his call to lawmakers Monday to overhaul the nation's immigration laws.

"Whether we will agree or not, I don't know," McCain told the more than 150 people gathered at a Phoenix community center.

McCain repeatedly urged civility during the meeting Monday, but he also stepped in and took sides.

He told the young woman who asked to be called an undocumented immigrant that he would continue to use the term illegal because it's accurate. Many civil rights and Hispanic groups consider the term illegal immigrant offensive.

"You can call it whatever you want. I think there is a big difference between someone who does something illegal and not being documented," McCain said, earning cheers from those opposed to immigration reform.

When immigration activists stood up to thank him for trying to get something done on the issue, McCain warned, "You are not going to be completely happy with this legislation."

At another point, McCain and some Hispanic activists laughed at a man who asked how he and other immigration critics could stop "amnesty." McCain also cut off a Mexican woman who said immigrants should come to the country legally as she did.

"It's not acceptable to have 11 million people living in the shadows of this country," McCain said. "If you believe they are not living in the shadows, I'd like to know what the hell shadows are?"

Reporting by The Associated Press.

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