Walid Phares has an article on The Counterterrorism Blog about homegrown terrorism highlighting the recent Najibullah Zazi, the Afghani terrorist and immigrant, terrorism case. Phares usually provides great insight into the problem of jihad, but he missed the real point in all the cases he documents on jihad in the U.S. Most were not "homegrown," but immigrants or direct decendants of immigrants. Only the South Carolina case involves native white Americans and the Alabama recruiter shooter was native, but black, and had been to Yemen. Even Zazi's co-conspirators were immigrants.
The problem is not so much jihad in the U.S. but a broken immigration and enforcement system that provides free access to the U.S. by jihadis. The problem is easy to solve. Stop allowing the entry of Moslems into the U.S. and remove the ones already here will end the problem of homegrown jihad.