Last week's terrorist attack in Nice, after similar tragedies in Paris, San Bernardino, Brussels, Orlando and Istanbul, made two things painfully clear. Western societies, including the United States, have failed to blunt the growing threat of Islamist terrorism. And that means the 2016 presidential campaign will be fought under a shadow of fear. There will be more attacks between now and November; the only questions are when and where.
Voters who began the year looking for a leader who could raise median incomes are now searching for someone who can keep their families safe. And the two major candidates are offering starkly different approaches — two different brands of toughness: hot and cool, outraged and wonky.
Donald Trump, with his visceral sense of the nation's mood, has bluntly voiced voters' anger and fear.
"If we don't get tough … we're not going to have our country anymore," he said after a New York-born Afghan American shot up a gay nightclub in Orlando, Fla., in June. "There will be nothing — absolutely nothing — left."
Trump has proposed banning Muslims from entering the United States, restoring waterboarding and "a hell of a lot worse" in interrogations, and killing the spouses and children of Islamic State militants (which would be a war crime).
On Thursday he warned that allowing Muslim refugees into the United States "could be the great Trojan horse of all time."
"We have no idea … who they are," he said. "They have no paperwork." (That claim is utterly false; most refugee applicants wait at least 18 months while they are investigated.)
As many national security experts have pointed out, Trump's proposed ban on Muslims would be counterproductive; it would alienate millions of people the United States wants to enlist in the war against Islamic State. It may even be a political loser for Trump. Although most Republicans agree with the proposed ban, most independents — voters he presumably needs in the general election — do not.
Still, Trump's white-hot rhetoric reinforces his image as a tough guy who's willing to do whatever it takes.
Hillary Clinton, with her decades of experience as a policy wonk, is sounding a tough note, too.
"This is a war against these terrorist groups, the radical jihadist groups. It's a different kind of war," she said last week. "We need to be smart about how we wage it, but we have to be determined that we're going to win it."
But her proposals are often cautiously hedged and wrapped in national security jargon.
She's called for "skillful diplomacy," for "a new look at our visa programs," for "building up a global counterterrorism infrastructure."
Clinton has proposed, essentially, to maintain President Obama's current strategy against Islamic State, but to do more and faster: more airstrikes, an "intelligence surge" and new measures to disrupt terrorists' social media networks. It's worth remembering that she's often been more hawkish than Obama, even when she served inside his administration.
If her approach is less memorable than Trump's, in the end, it's more sensible.
And voters have noticed. When asked which candidate they consider temperamentally suited for the presidency, Clinton wins in a walk. Even on the issue of terrorism, Trump doesn't appear to have an advantage.
In June, polls found that most voters thought Clinton could do a better job on terrorism, by a wide margin. More recent polls — taken when Clinton was in a general slump, probably because of the well-deserved shellacking she took from FBI Director James B. Comey over her private server — show the two candidates tied on terrorism. Even that's remarkable, though; terrorism should be an easy win for a GOP candidate. In 2008, on that issue, voters preferred Republican John McCain over Obama by a wide margin.
In the last few weeks, after his erratic, self-absorbed reaction to the Orlando tragedy was widely panned, Trump eased up on the bluster — a bit, anyway.
Now Trump has a golden opportunity to change the tone of his campaign for good: The weeklong nominating convention in Cleveland, at which he'll be center stage.
If he chooses, he can use the event to look more presidential, more deliberative, and readier to lead, erasing some of the stature gap, the temperament gap, the qualified-to-be-president gap that has kept him behind Clinton for most of the year.
There's at least one good reason, then, to keep an eye on the convention: We'll be able to tell whether Trump is trying to evolve by how he chooses to talk about terrorism.