Call it the fear factor.

That Americans are worried about terrorism is perhaps best evidenced by Donald Trump's lead among Republicans in national polls. The tougher his talk, the higher his numbers go. Trump wants to build a wall along our southern border, won't rule out a database on all Muslims, supports a database for refugees, claimed we should "take out" the family members of terrorists, and wishes to cease all immigration for Muslims. In spite of - or maybe because of - these positions, he has 36 percent of the Republican vote according to a recent CNN/ORC survey; his nearest competitor is Ted Cruz with 16 percent. And when GOP voters were asked which candidate is best able to handle ISIS, 46 percent said Trump, followed again by Cruz with only 15 percent.

A new Huffington Post/YouGov poll shows 64 percent of Americans believe it's more important for the United States to focus on preventing terrorism than on preventing gun violence. Additionally, 53 percent of respondents say issues related to terrorism will be "very important" when they vote next year.

But are our concerns about terror overblown? Yes, according to John Mueller, a political scientist at Ohio State and at the Cato Institute, and Mark G. Stewart, a professor of civil engineering at the University of Newcastle, Australia. They have just published Chasing Ghosts: The Policing of Terrorism, in which they argue that it's time to apply standard forms of cost-benefit analysis to our fight against terror, something we've not heard from any candidate.

"We do it with everything else," Mueller told me. "We do it with hurricanes. We do it with putting seat belts in cars. Is the hazard big enough to justify this kind of expenditure? So that's the procedure that should be used. But it mostly has not been done in the terrorism area, though it certainly has been done with natural hazards like earthquakes and also with things like nuclear radiation, a very emotive issue."

Mueller and Stewart note that, while the chance of an American being killed in the United States by a terrorist is only one in four million per year, around 40 percent of Americans profess that they worry they or a family member will become a victim of a terrorist. In comparison, the risk of being killed in an automobile is about 1 in 8,000 per year.

So why the disconnect? Because no one is willing to advance a case for fiscal prudence out of concern for being criticized as soft on terror. We see similar cowardice when it comes to the Pentagon budget. As a result, the relative cost of our antiterror measures is never debated.

Mueller and Stewart believe we face a real adversary, but question whether our chase is worth the cost. Mueller points out that, pre-San Bernardino, only 19 have died in the United States since 9/11 due to Islamic terror. Overall, they believe terrorists are given a disproportionate amount of credit for their prowess.

"In general, the capacities of those seeking, aspiring, or vaguely thinking about such terrorism, whether based in the United States or abroad, seem to be unimpressive, and any threat they present appears to be quite limited," they write in the book. Still, that hasn't stopped our elected officials from launching a disproportionate counterattack.

In the case of President George W. Bush, that meant in response to a tragedy that inflicted "perhaps $200 billion in direct and indirect costs, he created tragedies that were far greater: increases in domestic counter terrorism expenditures of over $1 trillion, and two wars that thus far have cost several trillion dollars, and have led to well over 100,000 deaths, including twice as many Americans as died on Sept. 11," they write.

So what is the more prudent path?

"The most important thing the government does is protect the public," Mueller said. "That's why people have governments. So the most responsible manner of doing that is to go through this kind of analysis to see whether an additional expenditure will reduce the risk enough to justify its cost. That's sort of hard-nosed stuff, but that's the way it has to be done. It's done in medicine all the time. They give vaccinations. They know some of those vaccinations are going to kill people, a very small percentage. But they have to look at that, and they talk to patients saying there's a very small chance this could really do damage to you, but mostly it's going to do good things. And overall the people are willing to accept those kinds of risks."

Mueller's reasoning made sense to another proponent of game theory, former poker champion and decision strategist Annie Duke, who said the approach is best regarded as "decision science."

"When we are doing cost-benefit analysis we get very different answers when thinking about an abstract situation vs. one that is personal and vivid," Duke said in an email. For example, in thinking about how much society should invest in a cure for a certain type of extremely rare cancer, an individual will give a different answer in the abstract (not very much) than if it is someone they know personally who has that cancer (much, much more). This is because the decision process moves out of the rational, analytic mind into the emotional mind."

"Terror is vividly depicted on the news, triggering fear in a way that imagining driving a car or swimming in a pool do not, both of which are vastly more dangerous than terrorism," Duke continued. "The heightened emotional reaction to reports of terror causes a rejection of traditional cost-benefit analyses on how much should be spent on preventing terror versus other threats to the public well-being since the threat of terror is so easily and vividly imagined."

Duke said many politicians make decisions about allocating resources - whether for repairing bridges, vehicle safety, drug abuse, or the war on terror - based on their short-term needs (getting elected now) instead of on the maximum benefits to society long-term.

"When the public is afraid and in a panic, as they are about the threat of terror," Duke said, "they want action now and the politicians will naturally align themselves with this short-term thinking to get elected."

The logic makes sense. But probably not in this campaign season.

Michael Smerconish can be heard from 9 a.m. to noon on Sirius XM's POTUS Channel 124 and seen hosting "Smerconish" at 9 a.m. Saturdays on CNN.