Michael Tanner of the Cato Institute devotes his latest National Review Online column to the partisans who are trying to take political advantage of the Boston Marathon bombing.

Even before doctors had finished treating the wounded, several senior Democrats told Politico that “the attack shows why Congress should’ve stopped automatic spending cuts from taking hold in March.” In particular, House minority whip Steny Hoyer pointed to the bombing as evidence that “we need to invest in our security” and not “pursue any irrational policies of cutting the highest priorities and lowest priorities by essentially the same percentage.” Democratic Policy Committee chairman Xavier Becerra went on to claim that the sequester had also hindered the response to the bombing. “We know that first responders are being cut,” he claimed, although there is little real evidence of such cuts. “We know that community police [are] being cut. We know that health-care services, especially emergency health-care services, are being cut.” Anonymous White House sources leaked that they were concerned about “the impact of the sequester on the short-term capabilities and long-term operations of homeland security.”

Former congressman Barney Frank went even further, linking the bombing to tax cuts and the entire movement for limited government, pointing out that “no tax cut would have helped us deal with this or will help us recover.

One imagines one of the Tsarnaev brothers suddenly announcing, “They’ve just cut federal spending by less than 2 percent. Quick, go get the bombs.”

Former White House chief of staff Rahm Emanuel once famously said that you should never let a crisis go to waste. President Obama and congressional Democrats have been quick to follow his advice. One need go no further than the president’s exploitation of the Newtown tragedy to see this principle in operation. There’s no reason to believe that there won’t be an attempt to use this horrible event similarly.

Not that Republicans have been immune to the temptation. Defense hawks are already seeing Boston as an excuse to avoid making scheduled defense cuts. But most defense spending has nothing to do with fighting the type of terrorism that we saw in Boston. What are we going to do: Fire a drone missile into Boston? Invade Dagestan?

Others have already called for more surveillance and new restrictions on privacy or civil liberties. But before we install a camera on every street corner, impose new gun-control measures, or censor the Internet, shouldn’t we at least pause to consider whether any of those things would have prevented this attack?