It is not entirely clear what inspired Omar Mateen to commit the worst mass shooting in U.S. history, or what might have been done to stop it.

But it happened in a gay club, just two weeks shy of the first anniversary of the U.S. Supreme Court decision legalizing same-sex marriage, and on a weekend when cities across the country, including Washington, were holding gay pride festivals.

It was perpetrated during the holy month of Ramadan by an American-born man whose family originally came from Afghanistan. During the attack, he reportedly made a 911 call pledging allegiance to the Islamic State.

He did it with a handgun and an AR-15 — the same semiautomatic rifle that was part of the arsenals used to kill 12 people in an Aurora, Colo., movie theater in 2012; 20 first-graders and six adults later that year in Newtown, Conn.; and 14 others at a holiday party in San Bernardino, Calif., last December.

It has always been true that the toughest issues are those that pit our values against our fears. And in this tragedy, as with so many before it, both parties are certain to seek political leverage.

Meanwhile, the country's anxieties have been rekindled. "In one sense, all of this seems so far out of control, you just wonder if there's any way of ever getting it under control," said George Pettice, an insurance agent from Charlotte, N.C. "Do we now start locking ourselves up in our houses, afraid to go anywhere?"

Not since 9/11 has a moment like this brought the nation together, and that evaporated quickly. Since then, calamity seems only to drive the left and the right further apart, while faith in the nation's institutions deteriorates further.

Across the ideological and partisan divide, it no longer seems possible to even explore — much less agree upon — causes and solutions. So the response has been muddled, even while the next tragedy looms.

"Although it's still early in the investigation, we know enough to say that this was an act of terror and an act of hate," President Obama said Sunday. "And as Americans, we are united in grief, in outrage, and in resolve to defend our people."

While Obama refrained from speculating about whether Mateen's religious beliefs might have been a factor in the rampage — or even saying the word "Islam" — he did make an appeal for tighter gun control.

"The shooter was apparently armed with a handgun and a powerful assault rifle," the president said. "This massacre is therefore a further reminder of how easy it is for someone to get their hands on a weapon that lets them shoot people in a school, or in a house of worship, or a movie theater, or in a nightclub."

"And we have to decide if that's the kind of country we want to be," Obama added. "And to actively do nothing is a decision as well."

Obama's comments reflected his frustration over the failure of his efforts to tighten the nation's gun laws following the Newtown massacre. Recent polling suggests that support for gun control is on the decline.

Critics, however, would argue that Obama's observation about doing nothing could also apply to failing to face up to the religious component of many acts of terrorism.

If Muslim beliefs were behind the attack, said Sen. Marco Rubio (R-Fla.), "common sense tells you he specifically targeted the gay community because of the views that exist in the radical Islamic community with regard to the gay community."

"I think it's something we'll have to talk about some more here, across the country," Rubio said.

Others pointed out that many other religions have no claim to moral superiority, when it comes to their attitudes toward gays, lesbians, bisexuals and transgender people.

"We want to get on the moral high ground when it comes to policing homophobia in other religions," ESPN commentator Jemele Hill, a former Orlando resident, said in an interview. "We're not the ones to be engaging in this, as if we have always been supportive of these issues. History says just the opposite."

Tough — and intolerant — rhetoric has often been a winner for politicians at times when Americans are worried about their security.

Trump, who advocates putting a temporary ban on Muslims entering this country, saw his poll numbers rise significantly in the wake of the San Bernardino attack, as well as after a series of terrorist assaults in Paris last November.

That may be why presumptive Democratic nominee Hillary Clinton struck a purposeful tone in her response to the Orlando mass shooting, although she, like Obama, did not make reference to a specific religion.

"For now, we can say for certain that we need to redouble our efforts to defend our country from threats at home and abroad," she said. "That means defeating international terror groups, working with allies and partners to go after them wherever they are, countering their attempts to recruit people here and everywhere, and hardening our defenses at home."

She, too, gave a nod to the need for tighter gun control, saying Orlando "reminds us once more that weapons of war have no place on our streets."

Yet there is danger in going too far to politicize a nation's grief, even if that happens smack in the middle of a presidential election year.

"The key thing here is, this was not a political event," said GOP pollster David Winston. "It is a tragedy the country has to deal with."

And perhaps, at some point, to demand a solution.