What is the issue the Palm Beach Post calls "almost the only topic" and the one that is "playing a pivotal" role in Florida's battle for the American Senate? It's not health care, taxes, education, the economy, or even Iraq. Rather, the two principal candidates are engaged in a ferocious argument over Sami Al-Arian, an accused Islamist terrorist. Their battle teaches lessons for the future.Mr. Al-Arian, a Palestinian immigrant, was a professor of engineering at the University of South Florida when in 1994, investigative journalist Steven Emerson aired a documentary establishing that, as president of the Islamic Committee for Palestine,...