Two successive weeks of political conventions meant to frame the November choice for president kick off this week nearly obscured by violence and terror here and abroad.
That has driven a fierce imperative during both gatherings, the Republican convention, which begins Monday; and next week's Democratic one: convince voters that the party nominee can be an effective leader in a world that seems distraught and divided.
The two presumptive nominees have offered voters very different responses to that need.
"Hillary is a weak person," Donald Trump said Saturday, referring to Democrat Hillary Clinton during a meandering introduction of his vice presidential pick, Indiana Gov. Mike Pence, in New York.
"We are the law-and-order candidates, and we're the law-and-order party. We're going to change things around."
Pence, following Trump's remarks, twice referred to Clinton with variations of the word "weak."
While Trump talks of strength, Clinton pushes steadiness. Her campaign released a video referring to Trump as "always divisive, not so decisive," as it recounted Trump's back-and-forth contradictions as he selected his running mate.
That came atop a television ad that showed Trump telling interviewer Chuck Todd that he got his military advice information from "the shows," referring to Sunday news programs.
"Hillary Clinton, a steady leader in an unsteady world," the ad concludes.
In marketing themselves to American voters, both candidates are operating from a posture of political weakness. Clinton and Trump are regarded negatively by a majority of Americans, meaning that both are trying to persuade voters who are, at least at this point, dissatisfied with their choice in November.
The lack of popularity on the part of either candidate could alter what has historically been the response to crisis: opting for the most experienced or publicly stable candidate.
In any other year that would be Clinton, a former first lady, U.S. senator and secretary of State. But concerns about her character and the reality that she is seeking a third successive term for Democrats—difficult under any circumstances--appear to have blunted her advantage over Trump.
The New York businessman, whose inexperience with foreign policy and military matters might otherwise have disqualified him during such turbulent times, benefited during the primary season as voters turned away from experience and toward a tough-talking, if detail-free, alternative.
Unknown at the moment is what would happen if similar disruptions persist through election day. Will Trump seem like strong presidential timber or an indecisive rookie? Will Clinton seem appropriately deliberate or the personification of the policies that contributed to American fears?
Recent polls suggest that voters are split over which candidate would be better when it comes to protecting the country against terrorism. In a new CBS News/New York Times poll, 46% of voters chose each candidate. In a McClatchy/Marist poll last week, Clinton had a statistically meaningless 1-point advantage over Trump.
In both polls, Clinton was seen as far more prepared than Trump to serve as president. But that marker was not compelling enough to dictate voters' choice: The two were tied in the CBS/Times poll, and Clinton had a mere 3-point lead in the McClatchy/Marist poll.
Their approaches as they try to surmount the political challenges to the outburst of violence here and abroad have diverged along the same lines seen elsewhere in the campaign.
Trump played to fear with an apocalyptic tone and few concrete solutions.
"Another horrific attack, this time in Nice, France. Many dead and injured. When will we learn? It is only getting worse," he said Thursday on Twitter.
In a later Fox News interview, he reiterated his plan to ban Muslims from countries involved in terrorism from entering the U.S.—he has not said which ones, or whether the list would include allies like France—and said that "we are in a world war scenario."
That was in keeping with his prediction earlier in the week, during an event in Indiana, that nearly a dozen U.S. cities were on the verge of exploding because of protests against police violence. He also asserted, without proof, that protesters had called for a moment of silence in honor of the gunman who shot five Dallas police officers this month.
Clinton has taken a more diplomatic tone. The U.S. had to work with other nations to defeat terrorism, she said as she warned against unilateral actions that would feed terrorist recruitment. She used as a case study the Obama administration's extensive efforts to find and capture Osama bin Laden before he was killed in a U.S. raid.
"It's a different kind of war, and we have to be smart about how we wage it and win it," she said Thursday during a telephone interview with CNN.
A ground war in Syria, of the sort that Trump appeared to be hinting at, would only boost the ranks of terrorists, she said.
"They would love to draw the United States into a ground war in Syria," she said. "They actually think the end times could be hastened, so we've got to be smart about this."
Both candidates face risk as they confront an environment churning with concern.
Clinton's campaign has been operating like a cohesive machine, and she has confronted crises with a sense of surety and deliberateness. That can be reassuring to some voters. But to others, it can seem to telegraph a lack of urgency, even if there are no swift solutions to the problem at hand.
Trump has the opposite problem. In trying mightily to adjust to a presidential campaign, he has demonstrated a capacity for disarray that to some voters could suggest lack of readiness for the White House.
His vice presidential search, the most high-profile event of his general election campaign to date, has been a prime exhibit of those shortcomings.
He undertook a public vetting of his options, lofting what is usually a quiet process to reality-TV levels. He said on Fox News on Thursday night that he had not made a final decision, but his selection, Pence, said that he had been offered the job on Wednesday.
Trump planned to announce his pick Friday, but after the killings in Nice postponed the scheduled appearance in deference, he said, to the victims. But then he tweeted his choice at the same time he was to have made it in public.
When he finally announced Pence's selection on Saturday, it came after a rambling speech in which he re-litigated his primary wins, highlighted Clinton positions that Pence shares, and made false claims about his own record.
The vice presidential choice technically had nothing to do with the world's tumult; nor will Clinton's, which will be announced within the week.
But the traits they illustrate are easily transferable, given the world's turmoil. From now on, everything the candidates do will be viewed through the lenses of steadiness and strength.