Seeking to make the Orlando shooting a major election issue, Donald Trump attacked Hillary Clinton and President Obama on Monday for an "incompetent" and "politically correct" approach to terrorism, while Clinton and other Democrats said the presumptive GOP nominee's rhetoric will only encourage more terrorist acts.

In addition to echoing his call for a temporary ban on Muslim entry into the U.S., Trump used a heavily promoted speech to say he would, as president, suspend immigration from "areas of the world when there is a proven history of terrorism," though he did not specify how those areas would be defined.

"This is a very dark moment in America’s history," Trump said during remarks in Manchester, N.H. "If we don't get tough, and if we don't get smart, and fast, we're not going to have our country anymore."

Responding to the Sunday attack that killed 49 people at an Orlando nightclub — the worst mass shooting in U.S. history — Trump pledged to tighten a "dysfunctional immigration system" and improve intelligence services that he claimed "cannot effectively check the backgrounds of people we’re letting into America."

In claiming he could suspend immigration from terrorist areas, Trump said the law gives presidents "powers to suspend entry into the country of any class of persons" if it is determined to be in the national interest.

Clinton, during a string of television interviews, told MSNBC that Trump and others are seeking to "demonize, demagogue and declare war on an entire religion" with comments that will inspire the Islamic State, also known as ISIS or ISIL, to call for more violence.

"That is just dangerous and it plays into the hands of ISIS and other jihadist terrorists," Clinton said.

In his speech, Trump — unusually aggressive for a political candidate so soon after a traumatic event — denounced Clinton as a "weak" leader who doesn't understand radical Islam and blasted her response to the Sunday mass shooting with calls for gun control.

Trump made mistakes in his speech. He said the killer in Orlando "was born in Afghan, of Afghan parents." In fact, Omar Mateen was born in the United States. Trump said Clinton wants to abolish the Second Amendment; Clinton says she supports gun rights, but wants new laws to help keep weapons away from potential terrorists.

As for Obama, Trump said that the president as well as Clinton are more interested in protecting the feelings of Muslims than in fighting terrorism, and "the current politically correct response cripples our ability to talk and to think and act clearly."

Trump even suggested earlier in the day that Obama may have some sort of sympathy for terrorists, telling Fox News that the president "doesn't get it or he gets it better than anybody understands ... This man has no clue."

White House spokesman Josh Earnest said the president has not hesitated to use the military against terrorists and made reference to the 2011 mission that killed 9/11 architect Osama bin Laden.

The president's record "speaks for itself," Earnest said, and "that record includes a lot of dead terrorists."

On Sunday, just hours after the shooting, Trump said Obama should resign and Clinton should withdraw from the race because they refused to use the term "radical Islamic terrorism." He redoubled his call for a temporary ban on Muslims entering the United States and said the country should be very restrictive in accepting refugees from Syria and other Middle East countries.

The presumptive Democrat presidential nominee, who also delivered a speech Monday in response to the Orlando attack, said Trump's argument about the term "radical Islamic terrorism" is irrelevant to the challenge facing the country.

"From my perspective, it matters what we do more than what we say," Clinton said on CNN, adding: "Whether you call it radical jihadism, radical Islamism, I think they mean the same thing. I'm happy to say either."

Some Republicans criticized Trump's speech, especially his criticism of Muslims. Tim Miller, an adviser to an anti-Trump political action committee, said Trump would replace Ronald Reagan's "shining city on a hill" with "we can't let these people in."

Trump's aggressive response to the attack is a striking contrast to the low-key reaction of political leaders to previous attacks like 9/11. Republican congressional leaders did not mention the Obama administration or the election in their responses to the massacre in Orlando.

Obama did not discuss the election in his remarks Sunday on the shooting, saying that, "as Americans, we are united in grief, in outrage, and in resolve to defend our people."

Democrats and others have criticized Trump for his post-attack comments, including a tweet in which he said he appreciated "the congrats for being right on radical Islamic terrorism."

Appreciate the congrats for being right on radical Islamic terrorism, I don't want congrats, I want toughness & vigilance. We must be smart!

— Donald J. Trump (@realDonaldTrump) June 12, 2016

Rep. Ben Ray Lujan, D-N.M., chairman of the Democratic Congressional Campaign Committee, said Trump's self-congratulatory tweet and other comments served only “to further incite the worst in people." Speaking with reporters at a breakfast hosted by the Christian Science Monitor, Lujan said that "words matter ... this is a very serious time. It demands very serious leadership.”

Republican pollster Frank Luntz noted that, during the Republican primary race, Trump appeared to benefit politically from similar responses to attacks in Paris and San Bernardino, Calif. It could happen again, Luntz said, because   "Americans are tired of the same useless, politically correct responses to terror.  They want someone who is as mad as they are and willing to do something about it."

Tommy Vietor, former spokesman for the National Security Council under President Obama, said no one can predict the political impact of the attack, but Trump's "despicable" comments are more evidence of his lack of qualifications for the presidency.

Julian Zelizer, a political historian who teaches at Princeton University, said there's usually "a pause" of at least a few days before candidates launch political attacks after violent events. But fierce debates over national security issues are common in elections, and will be again this year.

Trump's supporters will likely "connect the dots the way he does," while critics will wonder about his temperament and believe "he doesn't think think through carefully what he says," Zelizer said — and he 's unsure which number will be bigger.

Social media is playing a role in the immediate politicization of the Orlando attack, removing many filters over public discourse.

"Part of it is Trump," Zelizer said "Part of it is the age of Twitter."