Obama might have been able to find a prominent public health expert with gravitas and television skills to tap as the administration’s new Ebola tsar. He was probably wise to choose a political operative instead. For a political operative is more likely to convey to the White House that Ebola is not only a potentially very serious health problem, but a watershed for his administration—one with the potential to end the Obama presidency.

Should we assume that the chances of another Thomas Eric Duncan, the Liberian whose arrival here resulted in the infection of two nurses, are fairly small? Perhaps such a traveler would be screened under the new procedures and quarantined after arrival at an American airport, but why would he have been? Duncan’s temperature was supposedly normal when he boarded the flight from Liberia and was likely normal a day later, when, via Brussels, he arrived at Washington’s Dulles International Airport. He apparently flew during the latency period between infection with Ebola and the advent of discernable symptoms. What are the chances of that happening again? Well, negligible perhaps. But there are, according to the Center of Immigration Studies, more than 13,000 people from the three largest Ebola countries with visas to travel to the United States. How many of those might profile like Duncan? By continuing to allow flights from the Ebola countries, the Obama administration is placing a very steep wager that the number is zero.

One can notice that the broader political atmosphere has changed already. Granted, the Republicans were long favored to make off-year election gains; the president’s party almost always loses ground after six years. But the GOP had few serious issues to campaign about. Benghazi and the Affordable Care Act were, literally, the major GOP talking points for most of the past two years. The ACA is at worst a decent effort to mitigate a major problem that Republicans did nothing to address when they held the presidency and both houses of Congress, and Benghazi is a nothing burger if there ever was one. The GOP has no more persuasive answers to the emergence of ISIS in Iraq and Syria than Obama.

But now Republicans can talk about Ebola. Already there is a sea change in the political atmosphere; In The Weekly Standard, Jonathan Last has published an excellent article about the Ebola crisis; highly readable Wall Street Journal columnist Peggy Noonan effectively deconstructs the patronizing rhetoric coming from the Washington Ebola establishment. Many who are not fans of either publication will find the pieces compelling. When, in a widely watched, highly competitive swing state senate race, a Democratic incumbent feels the need to break openly with Obama’s “let the Liberians fly in” stance, it should signal to the White House that its position is politically untenable. That is, assuming the White House is sufficiently open to unpleasant political information to read the tea leaves.

Obama would upset virtually no one if he said, until things are under better control, no travelers from the most infected countries will enter legally through American airports. There really is no serious constituency opposing a temporary flight ban. Because the severely affected countries need help, the administration can and should arrange charter flights to fly health care workers in and out. A flight ban would not be the kind of “error on the side of prudence” (like, for instance, interning Japanese Americans during World War II) that violates the rights of American citizens. The fact is, West Africans have no “right” to fly here. The science about the disease’s transmission (as Jonathan Last points out) is more murky and less reassuring than the administration claims. But even under best-case assumptions, if someone like Thomas Duncan, a symptomless Ebola carrier arrived here tomorrow, there is no way he would be stopped or quarantined. To regular Americans, including most Obama supporters, this seems like dogmatic adherence to abstract principle (America’s borders should be open to the world) over simple common sense. If more Africans from the three infected countries fly here and make more nurses sick, there is a fair likelihood that Obama would be successfully impeached.

I write, it could be noted, as an Obama supporter, as someone who volunteered in both presidential campaigns. His nearly six years in office have been somewhat of a disappointment, but my expectations were always modest. Obama steered the country fairly successfully through the mortgage crisis, following Wall Street friendly policies—to the monumental chagrin of some of his most eloquent backers. He tried to push Israel and the Palestinians towards a two-state solution, eventually realizing that his leverage to bend Israel towards justice was not up to the task. He has been unable to stand up to the defense establishment on the issues of torture or domestic surveillance. But more often than not he has tried to resist hawkish policies; we haven’t started a war against Syria, we haven’t started one against Iran, we haven’t started one against Russia. There is a powerful permanent government in Washington whose default position on all international crises is always hawkish, and Obama—if he hasn’t defeated it, has managed with some success to rope-a-dope it. Before the hawks, Obama has bent but not broken.

Moreover, I believe there is at least a 50 percent chance Obama will be able to do something truly historic—forge a new relationship with Iran, that will be a strategic boon to the United States and may even change—for the better—the trajectory of the Islamic world. This is no easy matter; it will require, for instance, effectively circumventing the wishes of the Israel lobby in ways no president has even thought about in more than 20 years. But there are grounds for optimism, and a detente with Iran will be as game changing—and necessary—as Nixon’s opening to China. Hillary Clinton would not have done this, nor John McCain. Obama may, and it will give a permanent luster to his legacy.

So I’m hoping that even if Ron Klain knows nothing much about Ebola, his counsel about American politics will be persuasive. I would now wager that the United States will suffer well less than a thousand deaths from Ebola before it’s over, that the disease never blossoms into the feared pandemic. Of course it might turn out worse, through no fault of the administration. About the politics, I’m far more certain. If Americans die because West Africans are allowed to continue flying here legally during the heat of the crisis, Obama’s presidency will be toast.

Scott McConnell is a founding editor of The American Conservative.