One reason Donald Trump can profit from his rabid fearmongering is because there's no one out there to calm the nation down.

According to a new New York Times/CBS News poll, Americans are more fearful about the likelihood of another terrorist attack than at any time since right after 9/11. A plurality of the public views the terrorist threat as the top issue facing the nation.

Americans need a leader they trust who can assure them that everything possible is being done to secure the country. Ideally, that leader should be President Obama, who tried to provide such assurances in his Oval Office address to the nation right after the San Bernardino shootings.

He did not succeed. His failure helps explain why a climate of panic is fueling the most ugly election season in decades.

According to the New York Times poll, 57 percent of Americans disapprove of Obama's handling of terrorism and the threat from ISIS, while seven in 10 say the fight against ISIS is going badly. In other words, a rare Oval Office speech did little to calm America's angst.

But here's an important news bulletin: Americans don't see Donald Trump as their savior, either. Despite Trump's rising support among Republican primary voters, the Times poll shows that 64 percent of the broader electorate would be concerned or scared about what he would do as president.

This confirms my belief that most Americans have not lost their minds.

However, Obama's inability to assuage the public's legitimate fears creates continued openings for demagoguery in a vicious campaign season. That failure goes beyond the serious weakness in his policies and plans.

After all, it's not the details of Mideast policy that are drawing crowds to hear the Donald.

Trump has no policy except to "bomb the s- out of them [ISIS]." Nor have his GOP rivals come up with much better (Ted Cruz's answer is to "carpet-bomb them into oblivion").

Hard-core conservatives who adore Trump are finding reassurance in bluster and bombast, not policy details. I believe many other Americans are looking for something more.

I won't deny a big part of Obama's problem is that he is selling an incoherent Mideast policy. His speech merely tweaked that policy and called for the public to be patient. "Our success won't depend on tough talk," the president said.

But the president never explained why coalition airstrikes in Syria and Iraq would work now, when they have proved inadequate up until now. There is still no effective Sunni Arab fighting force on the ground to call in targets or take advantage of U.S. air power. Nor did Obama explain how sending 50, or 150, more U.S. Special Forces can remedy the lack of Sunni ground troops. (America's Kurdish allies cannot and will not vanquish ISIS on their own.)

Moreover, the president still rejects any criticism of his refusal to help Syrian moderate fighting groups in 2012 (when they existed) or to arm Iraqi Sunni tribesmen eager to fight ISIS. This creates a gaping hole in his policy that the public grasps.

Instead, Obama and his team are betting that Vladimir Putin will endorse a peace plan that will end the fighting in Syria, dump President Bashar al-Assad, and unite the West, Russia, and the Syrian army to fight ISIS. To put it kindly, this is a mirage.

So, yes, the president's policies stoke public anxieties. But he also lacks the empathy to reassure the public (a quality that would ameliorate some of the unease over his policies). Americans need someone who can talk to them straight, without appealing to hatred or xenophobia or fear.

That means a leader with the FDR touch, who could reassure Americans of their strengths and of his commitment to fight Islamist terrorists, while pulling no punches about the complexities and difficulties. That reassurance was sadly lacking in Obama's Oval Office speech, as he stood professorially behind a lectern - displaying his famous cool, lawyerly demeanor. Missing was the behind-the-desk warmth of Roosevelt's "fireside" radio chats.

Feeling leaderless and rudderless, even some Americans who would normally reject a demagogue may succumb to the appeal of a strongman. I don't believe the Donald will make it to the White House. But I fear this election season will get even uglier - unless a candidate emerges who can speak intelligently to the American people, while calming their fears and allaying the hysteria that pervades this campaign season.

Here lies a huge opportunity for Hillary Clinton. Her recent foreign-policy speech in Washington had a strong, compassionate tone, but she is just laying out her foreign-policy program. The big question of this campaign as I see it is: Will Clinton rise to this opportunity, and in good time?