that proves my point

One of the techniques I learned in competitive debate was to look for ways that an opponent's key fact or argument could be used to support my own case. I thought I was being clever but now realize I was just engaging in sophistry. As are a lot of political commentators with supposed lessons from the Boston marathon bombings.  We are also seeing a lot of the "now more than ever" gambit, where advocates claim that the best solution to whatever the new problem is should be whatever they have long proposed in different circumstances.

Accordingly, we have calls for treating the surviving suspect as an "enemy combatant," despite his U.S. citizenship and a crime committed on U.S. soil. This allows them to defend the military tribunal system and Guatanamo prisons, despite Supreme Court rulings. This also constitutes a sneaky rejection of the Miranda ruling by the liberal Warren Court.

As Conor Friedersdorf argues, many of the Iraq war advocates, whose judgment should be discredited, are now calling for preemptive action abroad to somehow prevent homegrown terrorists.

Others are casting aspersions at Muslims, as if banning that religion or its practice within our borders would make our streets safe again. Marc Ambinder skewers their arguments.

These recycled hatreds and prescriptions should have been left in the compost pile.