Alternating between giddiness and focused attention, a cross-section of American youth debated immigration reform yesterday in an innovative videoconference centered in Philadelphia and sponsored by the National Constitution Center.

Challenged by the prompt, "Should the United States reduce immigration?" the selected students from several high schools in Pennsylvania, Ohio, Kentucky, New York, and California were linked via closed-circuit TV and watched one another on large, subdivided video monitors.

"We should reduce immigration. Our environment can only support a certain number of people," said Matt Hope, 17, of Wilson High School, near Reading. "As a pragmatic issue, we can't let everyone in."

While expressing empathy for immigrants who want to come to America to seek better lives, a student identified only as Ellen from Mohawk High School in Sycamore, Ohio, said, "We can't be the safe haven for everyone in the world."

Seconding that thought was Tom Emberger, 15, of Northeast Philadelphia, a sophomore at MaST Charter Community High School.

"We can't be sentimental," Emberger said. "If an immigrant can't get into the country we can feel sorry for him . . . but our government is supposed to take care of the people who are already here."

Piping in from Menifee County High School in rural Frenchburg, Ky., a student identified only as Keenan provided counterpoint.

"We say, 'No, don't reduce immigration,' " he said, speaking from the heart of tobacco country, where many of the farmhands are undocumented immigrants.

"People say illegal immigrants take away jobs," Keenan said. But "cheap immigrant labor is one of the things that can make or break these small farms. . . . Besides, this country was founded by immigrants."

From St. Agnes Upper School in Memphis, Tenn., a girl identified only as Corey said immigrants, regardless of their legal status, "should have the opportunities to have the opportunities we have."

Though students' opinions varied widely about what types of reforms were needed to turn the tide of illegal immigration or to deal with the estimated 12 million undocumented immigrants already here, "there seems no debate that our system is clearly broken," said the program's moderator, Su Chin Pak.

J. Michael Hogan, codirector of the Center for Democratic Deliberation at Pennsylvania State University, is a scholarly adviser to the videoconferences, which are part of "Exchange," a series on thorny social problems.

"A debate suggests there are just two sides to an issue," Hogan told the students yesterday. "But there are a lot of different perspectives on immigration. We have a lot of hope that you young people will teach us how to deliberate better."

Before the program got under way, Ukranian-born Mykhalo Gopka, 17, a senior at MaST, said approximately 80 percent of his class favored reducing immigration when the students began studying the issue in his government class. As alternative ideas were aired, he said, the class breakdown became closer to 50-50.

He still takes a hard line. "People come to America for a better life, to escape poverty or oppression," he said. "But if too many people come in, the U.S. will eventually become what everyone was trying to escape."

As in any discussion of American immigration, the famous motto on the base of the Statue of Liberty eventually was invoked: "Give me your tired, your poor, your huddled masses yearning to breathe free."

Michael Brown, 16, a MaST sophomore, said he would first ask illegal immigrants, "Why are you coming here to better your lives but start out by breaking one of our laws?"

He favored stricter border controls and a tough quota system for deciding who gets in: "What happens when we run out of room for immigrants? We need to start teaching them now that 'no' means 'no.' "

Though the students were open and civil with one another, Emily, from Jamestown High School in Jamestown, N.Y., couldn't resist a parting shot.

After apologizing that she couldn't quote the Statue of Liberty's motto precisely, she said, "I'm pretty sure it doesn't say, 'No means no.' "

Contact staff writer Michael Matza at 215-854-2541 or mmatza@phillynews.com.