obama responds radical islam label criticism bts_00000101.jpg
obama responds radical islam label criticism bts_00000101.jpg
Now playing
04:29
Obama fights back against terrorism rhetoric critics
exp orlando nightclub shooting timeline kaye pkg ac_00003416.jpg
PHOTO: WKMG
exp orlando nightclub shooting timeline kaye pkg ac_00003416.jpg
Now playing
02:52
How Orlando shooting unfolded, as seen via texts
exp  fire lieutenant on duty during orlando shooting brooke baldwin intv ac_00010130.jpg
exp fire lieutenant on duty during orlando shooting brooke baldwin intv ac_00010130.jpg
Now playing
02:02
First responder on Orlando shooting
Orlando the city beautiful strong orig_00013107.jpg
Orlando the city beautiful strong orig_00013107.jpg
Now playing
01:42
Orlando: The city beautiful
WASHINGTON, DC - JUNE 14: (AFP-OUT) US President Barack Obama speaks on the Orlando shooting at the Treasury Department after convening with his National Security Council on June 14, 2016 in Washington, DC. Obama directly attacked Donald Trump
PHOTO: Pool/Getty Images North America/Getty Images
WASHINGTON, DC - JUNE 14: (AFP-OUT) US President Barack Obama speaks on the Orlando shooting at the Treasury Department after convening with his National Security Council on June 14, 2016 in Washington, DC. Obama directly attacked Donald Trump's proposal to ban Muslims from entering the United States. (Photo by Jim Lo Scalzo-Pool/Getty Images)
Now playing
01:36
Key moments: Obama's 'radical Islam' pushback
orlando shooting seddique mateen lemon ctv intv_00003610.jpg
PHOTO: CNN
orlando shooting seddique mateen lemon ctv intv_00003610.jpg
Now playing
01:39
Orlando shooter's dad: I didn't notice anything
The Orlando Police Department released this photo of Omar Mateen, the person identified as the shooter in the Orlando terror attack.
PHOTO: Orlando Police Department
The Orlando Police Department released this photo of Omar Mateen, the person identified as the shooter in the Orlando terror attack.
Now playing
01:23
Officials: FBI had investigated Orlando gunman
Orlando Police officers direct family members away from a multiple shooting at a nightclub in Orlando, Fla., Sunday, June 12, 2016. A gunman opened fire at a nightclub in central Florida, and multiple people have been wounded, police said Sunday.
PHOTO: Phelan M. Ebenhack/AP
Orlando Police officers direct family members away from a multiple shooting at a nightclub in Orlando, Fla., Sunday, June 12, 2016. A gunman opened fire at a nightclub in central Florida, and multiple people have been wounded, police said Sunday.
Now playing
01:28
How the Orlando nightclub shooting unfolded
marco rubio orlando shooting wolf intv_00000424.jpg
marco rubio orlando shooting wolf intv_00000424.jpg
Now playing
01:34
Rubio on shooting: I fear 'we will see more of this'
An image taken from Omar Mateen
PHOTO: Omar Mateen/Myspace
An image taken from Omar Mateen's Myspace page. Law enforcement sources identified Mateen as the shooter in the Orlando terror attack.
Now playing
02:21
Gunman called 911, claimed allegiance to ISIS
Orlando shooting gunman ex wife presser bts_00002018.jpg
Orlando shooting gunman ex wife presser bts_00002018.jpg
Now playing
01:09
Ex-wife of Orlando shooter speaks out
A shooting and multiple injuries were reported at Pulse nightclub in Orlando.
PHOTO: Orlando Police
A shooting and multiple injuries were reported at Pulse nightclub in Orlando.
Now playing
02:20
Eyewitness records video of police storming club
president obama orlando shootings press conference sot_00004511.jpg
PHOTO: CNN
president obama orlando shootings press conference sot_00004511.jpg
Now playing
00:47
Obama: This was an attack on all of us
Now playing
02:44
Witness: 'No bullet could ever break a friendship'
orlando shootings muslim leader_00000919.jpg
orlando shootings muslim leader_00000919.jpg
Now playing
01:08
Muslim leader to ISIS: 'You do not speak for us'
PHOTO: WFTV
Now playing
01:10
Mayor: 50 dead in Orlando nightclub shooting
orlando shootings dj ray rivera burnett intv_00001130.jpg
orlando shootings dj ray rivera burnett intv_00001130.jpg
Now playing
01:04
Pulse DJ recounts shooting inside Orlando nightclub
orlando nightclub shooting witness sot_00000318.jpg
PHOTO: WKMG
orlando nightclub shooting witness sot_00000318.jpg
Now playing
00:55
Witness: 'Blood everywhere' after Orlando club shooting
orlando shootings victims names_00003311.jpg
orlando shootings victims names_00003311.jpg
Now playing
00:34
Victims in the Orlando shooting named
Orlando shooting medical response brown beeper_00011112.jpg
PHOTO: WFTV
Orlando shooting medical response brown beeper_00011112.jpg
Now playing
02:11
How did the Orlando medical center respond?
orlando nightclub shootout vo wolf_00003410.jpg
PHOTO: Anthony Torres
orlando nightclub shootout vo wolf_00003410.jpg
Now playing
00:48
Orlando nightclub shootout caught on camera
December 16, 2012 -- The shooting at Newton killed 20 children and six adults. At the memorial service, President Obama also cited the deadly shootings at Oak Creek and Aurora. "In the coming weeks, I will use whatever power this office holds to engage my fellow citizens -- from law enforcement to mental health professionals to parents and educators -- in an effort aimed at preventing more tragedies like this," said the president.
PHOTO: MANDEL NGAN/AFP/Getty Images
December 16, 2012 -- The shooting at Newton killed 20 children and six adults. At the memorial service, President Obama also cited the deadly shootings at Oak Creek and Aurora. "In the coming weeks, I will use whatever power this office holds to engage my fellow citizens -- from law enforcement to mental health professionals to parents and educators -- in an effort aimed at preventing more tragedies like this," said the president.
Now playing
02:34
How Obama responds to shooting attacks
Orlando police officers seen outside of Pulse nightclub.
PHOTO: Gerardo Mora/Getty Images
Orlando police officers seen outside of Pulse nightclub.
Now playing
05:24
Witness: We thought gunshots were 'part of the music'
orlando shootings hamid karzai intv_00000418.jpg
orlando shootings hamid karzai intv_00000418.jpg
Now playing
01:15
Former Afghan President condemns deadly Orlando attack
A target sheet hangs at a shooting range July 22 in Aurora, Colorado.
PHOTO: Getty Images
A target sheet hangs at a shooting range July 22 in Aurora, Colorado.
Now playing
02:20
How police train for active shooter response
psychology of terror sanjay gupta nws orig_00002811.jpg
PHOTO: ISIS
psychology of terror sanjay gupta nws orig_00002811.jpg
Now playing
01:25
The psychology of terror
orlando nightclub shooter omar mateen photo tapper _00000301.jpg
PHOTO: Facebook
orlando nightclub shooter omar mateen photo tapper _00000301.jpg
Now playing
02:22
Orlando nightclub shooter identified
Handguns that were swapped for gift cards during a Los Angeles Police Department sponsored gun buyback event in Los Angeles, California on December 13, 2014.  The city held the event in three locations and the public were able safely and anonymously surrender firearms in exchange for $100 and $200 gift cards.    AFP PHOTO/MARK RALSTON        (Photo credit should read MARK RALSTON/AFP/Getty Images)
PHOTO: MARK RALSTON/AFP/AFP/Getty Images
Handguns that were swapped for gift cards during a Los Angeles Police Department sponsored gun buyback event in Los Angeles, California on December 13, 2014. The city held the event in three locations and the public were able safely and anonymously surrender firearms in exchange for $100 and $200 gift cards. AFP PHOTO/MARK RALSTON (Photo credit should read MARK RALSTON/AFP/Getty Images)
Now playing
02:19
Survivors of gun violence are fed up
orlando nightclub shooting police press conference sot_00001921.jpg
PHOTO: WKMG
orlando nightclub shooting police press conference sot_00001921.jpg
Now playing
01:39
Police: Approx. 20 dead in Orlando nightclub shooting
A shooting and multiple injuries were reported at Pulse nightclub in Orlando.
PHOTO: Orlando Police
A shooting and multiple injuries were reported at Pulse nightclub in Orlando.
Now playing
01:25
Police: Shooter inside the nightclub is dead
orlando pulse club shooting update newday_00013602.jpg
PHOTO: WKMG
orlando pulse club shooting update newday_00013602.jpg
Now playing
02:18
Police: 'Mass casualty situation' at Orlando nightclub
florida nightclub shooting sanchez cnn nr lklv_00005304.jpg
florida nightclub shooting sanchez cnn nr lklv_00005304.jpg
Now playing
02:33
Several injured in Florida nightclub shooting

Story highlights

"We are now seeing how dangerous this kind of mindset and this kind of thinking can be," Obama said

Obama also called for Congress to pass tougher gun laws and the renewal of the assault weapons ban

(CNN) —  

President Barack Obama lit into Donald Trump Tuesday, turning the tables to make the impassioned case that Trump is the one who’s un-American.

Obama’s extraordinary denunciation of the presumptive Republican presidential nominee was about far more than a personal intervention on behalf of Hillary Clinton in the ugly general election campaign.

The commander in chief’s fury, which seethed out of him in a stunning soliloquy on live television, amounted to a moment of historic significance: a president castigating one of the two people who could succeed him as beyond the constitutional and political norms of the nation itself.

Obama’s remarks, motivated by his disgust over Trump’s response to the worst terror attack since 9/11, were also deeply ironic, given that Trump has hounded him for years with insinuations that he’s not a real American.

The real estate mogul had returned to that theme on Monday, hinting that in some way the President was complicit or approved of Islamic terror attacks, saying on Fox News, “There is something going on.”

Trump has based his attacks on conspiracy theories that Obama was born outside the country or a closeted Muslim. Obama’s charge, in contrast, was based on his perception that the billionaire Republican’s views are so extreme that he threatens the fabric of America itself.

RELATED: Donald Trump, Hillary Clinton showcase clashing styles at times of crisis

And Obama sought to shame Republican leaders, many of whom were left squirming by Trump’s views. Though they differ with many of his views – House Speaker Paul Ryan again on Tuesday rejected the GOP presumptive nominee’s stance on Muslims – they are trapped by his millions of primary voters, who made it clear to the party leadership that the billionaire businessman should be heeded.

“That’s not the America we want,” he said. “It doesn’t reflect our democratic ideals. It will make us less safe.”

Obama also drew an implicit analogy between Trump’s call for a ban on Muslim travel and the most “shameful” moments in American history when the government had mistreated its people, adding that then Constitution prohibited religious tests.

“If we ever abandon those values, we would not only make it a lot easier to radicalize people here and around the world, but we would have betrayed the very things we are trying to protect,” Obama warned.

Trump responds

Trump responded to the President during his Thursday night rally in Greensboro, North Carolina, saying Obama “was more angry at me than he was at the shooter.”

“The level of anger, that’s the kind of anger that he should have for the shooter and these killers that shouldn’t be here,” Trump added, blasting Obama as a “lousy president” who had done a “terrible job.”

Obama has pilloried Trump before. But Tuesday’s remarks displayed a deeper intensity and anger, reflecting his apparent belief that America had reached a dangerous moment given Trump;s new status as the presumptive Republican presidential nominee.

“I think the key for President Obama – is he is talking to the world,” presidential historian Douglas Brinkley told CNN’s Anderson Cooper. “Donald Trump isn’t just a candidate who a few months back was talking about banning Muslims from the United States. He has got a lot of momentum.”

He continued, “President Obama wanted to make clear that the United States government, the federal government says no to what Donald Trump is suggesting, that it is hateful bigotry.”

He concluded, “There was ire in his eyes and sarcasm in the way he went after Trump.”

RELATED: Obama to travel to Orlando on Thursday

Obama told his aides on Monday that he wanted to deliver a speech rebutting the Republican nominee’s comments after stewing over them, a senior administration official told CNN’s Dana Bash.

The result was the kind of public venting that Obama, one of the world’s most self-contained politicians, rarely indulges in publicly – though this side of his character is familiar to those who have witnessed the much more impassioned rhetoric he adopts in private.