"We have our immigration laws for two reasons. One, to protect our national security. And two, to protect American jobs," he said.

The national security component of the immigration debate could become a focal point in the aftermath of the Boston bombing. Both suspects came to the United States legally from abroad.

While their motives have not been definitively ascertained, they are already being mentioned as a cautionary tale by skeptics of immigration reform, including Republican Senator Chuck Grassley.

"How can individuals evade authority and plan such attacks on our soil,?" he asked. How can we beef up security checks on people who wish to enter the United States? How do we ensure that people who wish to do us harm are not eligible for benefits under the immigration laws, including this new bill before us?"

Gang of Eight senators are predicting long and fierce debate on immigration reform. Democratic Senator Charles Schumer:

"There will be perils we cannot even anticipate, but we start off with optimism, because this bipartisan agreement gives us a sturdy ship to ride out the stormy seas ahead," he said.

More about the Boston bombing could be learned if the surviving suspect recovers from wounds sustained in a gun battle with police and shares information with interrogators. Meanwhile, the debate on immigration reform is moving forward at the Capitol.