What’s more, the supposed “solutions” were similar, too, in their combination of cruelty and stupidity. Does anyone remember Mr. Trump declaring that “the plague will start and spread” in America unless we immediately stopped all plane flights from infected countries? Or the fact that Mitt Romney took a similar position? As it turned out, public health officials knew what they were doing, and Ebola quickly came under control — but it’s unlikely that anyone on the right learned from the experience.

What explains the modern right’s propensity for panic? Part of it, no doubt, is the familiar point that many bullies are also cowards. But I think it’s also linked to the apocalyptic mind-set that has developed among Republicans during the Obama years.

Think about it. From the day Mr. Obama took office, his political foes have warned about imminent catastrophe. Fiscal crisis! Hyperinflation! Economic collapse, brought on by the scourge of health insurance! And nobody on the right dares point out the failure of the promised disasters to materialize, or suggest a more nuanced approach.

Given this context, it’s only natural that the right would seize on a terrorist attack in France as proof that Mr. Obama has left America undefended and vulnerable. Ted Cruz, who has a real chance of becoming the Republican nominee, goes so far as to declare that the president “does not wish to defend this country.”

The context also explains why Beltway insiders were so foolish when they imagined that the Paris attacks would deflate Donald Trump’s candidacy, that Republican voters would turn to establishment candidates who are serious about national security.

Who, exactly, are these serious candidates? And why would the establishment, which has spent years encouraging the base to indulge its fears and reject nuance, now expect that base to understand the difference between tough talk and actual effectiveness?

Sure enough, polling since the Paris attack suggests that Mr. Trump has actually gained ground.

The point is that at this point panic is what the right is all about, and the Republican nomination will go to whoever can most effectively channel that panic. Will the same hold true in the general election? Stay tuned.