The young adults are part of the movement of immigrants who grew up in this country without legal status who call themselves Dreamers. Their parents traveled to the Mexican side of the fence from Brazil, Colombia and Guadalajara, Mexico, seeing their children in person for the first time in many years.

The meeting, under a searing borderlands sun, was a new piece of the highly personal political theater that young immigrants have used to dramatize their support for a bill in the Senate to overhaul the immigration system. Hours before the encounter here, President Obama spoke at the White House to urge Congress to move quickly to pass the bill. Suggesting the growing influence of the youth movement in the debate, the president framed his remarks — both literally and politically — with Dreamers.

snip

“This is not an abstract debate,” Mr. Obama said. “This is about incredible young people who understand themselves to be Americans, who have done everything right but have still been hampered in achieving their American dream.”