STEWART BAKER: Why wasn’t Tsarnaev searched at the border? “The lack of a ping upon Tsarnaev’s return to the United States suggests a gap in US border defenses. In general, the outbound ‘ping’ is not a big deal. It tells us that a terror risk is leaving the country, more a matter for celebration than suspicion. We don’t usually inspect or question departing passengers, so it would have taken a pretty unusual notice to earn Tsarnaev much scrutiny on departure. But his return should have been different. He was entering the country, and at the border the government’s authority to stop travelers, to question them, and to search their luggage, including their electronics, is at its zenith. If we have any doubts about the intentions of a returning green-card holder, this is the time and place to question him. When the FBI paid a visit to Tsarnaev’s home, Tsarnaev had complete control of the interview. He could throw the agents out whenever he chose, and he could certainly refuse to let them look at his computer and phone. At the border, though, he can’t. We could have learned a lot more about Tsarnaev’s journey into radicalism there.”

Yes, but he wasn’t a Tea Partier, so what were the odds he’d be a terrorist?