Donald Trump celebrated his 70th birthday in North Carolina with a serenade from an estimated 9,000 people and a vicious rebuttal to an afternoon of attacks lodged by Hillary Clinton and the president they both hope to replace.

'Happy birthday? Ah, don't tell me about my birthday!' he grinned as the singing started.

Trump's smile turned quickly into a pointed glare, though, as he blamed 'weak, ineffective people' in President Barack Obama's administration for what he said was an out-of-control immigration problem linked to the weekend's gun massacre at a gay nightclub in Orlando, Florida.

In a rare break from the no-drama-Obama voters have come to expect, the president unleashed an angry lecture on Trump in the afternoon, painting him as a know-nothing poseur whose lack of nuanced foreign policy knowledge and china-shop-bull approach to diplomacy would threaten to turn the Arab world against Americans and radicalize a new generation of Islamist jihadis.

Trump scoffed.

Scroll down for video

HAPPY BIRTHDAY TO TRUMP: The presumptive Republican presidential nominee turned 70 on Tuesday and celebrated in Greensboro, North Carolina by clobbering Barack Obama and Hillary Clinton as too weak to handle terror threats against the U.S.

PICKING A FIGHT: Trump said Obama sounded more angry at him during his noontime remarks than he did at the Islamist radical who killed more than four dozen people Saturday night at a gay nightclub in Florida

HE'S BACK: Trump recaptured the primary election magic for a crowd estimated at 9,000

'I watched President Obama today. And he was more angry at me than he was at the shooter!' he marveled.

'The level of anger – that's the kind of anger he should have for the shooter, and these killers that shouldn't be here.'

And the presumptive Republican presidential nominee dismissed Obama's law-school oration questioning the value of branding extremist attacks as the work of 'radical Islamic terrorism' – a seldom-heard turn of phrase Trump has used for months to clobber reticent Democrats.

Trump said the U.S. had no hope of maintaining homeland security 'if you don't know what the term is, and if you don't discuss what the problem is, and if you can't say the real name.'

'We have a radical Islamic terrorism problem, folks,' he argued. 'We can say we don't. We can pretend like Obama that we don't, where Obama spent a long time talking about it and nobody at the end of that speech understood anything other than, "Boy, does he hate Donald Trump".'

Trump has sought for the past 48 hours to tie the Orlando murders to a lax immigration program that admits too many loosely screened Arabs, and to Clinton's pledge to increase America's commitment to resettle Syrian refugees by 550 per cent.

'Every year we bring in more than 100,000 lifetime immigrants from the Middle East, and many more from Muslim countries outside of the Middle East,' Trump said.

'A number of these immigrants have hostile attitudes toward women, toward gays and people of different faiths,' he added, claiming that 'Hillary Clinton's immigration plan would bring in millions of unvetted immigrants – or very poorly vetted – and how can you vet somebody when you have no idea where they come from, you have no idea about the paperwork?'

'It doesn't take a big percentage' to be deadly, he said. 'Look what one whack-job – look at this one whack, this one horrible savage – look what he did in a short period of time to great young people!'

CLASS IS IN SESSION: President Obama lectured Trump during public remarks on Tuesday afternoon about America's war against the ISIS terror army and the Republican candidate's desire to link Saturday night's terror attack with the White House's immigration policies

WEDGE ISSUE: Trump continued to blast Hillary Clinton as a weak ally of women and gays because she advocates immigration policy that he says would result in importing more radical Muslims who oppress both groups

Trump extended his circle of suspicion on Tuesday night to the Orlando attacker's in-laws, likely unaware that FBI agents were raising their California home as his motorcade was en route to the arena.

'Now there are reports that ... the second wife knew about the attack but may have not told the authorities,' he said of the Florida massacre.

'Nobody really knows. Her family reportedly is from Afghanistan.'

Clinton and Obama spent part of Tuesday arguing that the Muslim man who killed more than four dozen people in the wee hours of Saturday night was himself a native-born American.

But 'the killer's parents emigrated from Afghanistan,' Trump told his crowd, citing news reports that 'the children of Muslim immigrant parents are responsible for a growing number, for whatever reason, a growing number of terrorist attacks.'

'The killer's Afghan father supported the Taliban, which believes in violently oppressing women and gays,' Trump fumed.

'Once again we've seen that political correctness is deadly. They don't want to talk about the problem,' he said.

Trump continued to wind a thread from his Monday speech in New Hampshire, where he argued that Clinton is a poor representative for women and homosexuals because she has enabled a wave of immigrants from countries known for oppressing and abusing both groups.

'We want to live in a country where gay and lesbian Americans and all Americans are safe from radical Islam – which, by the way, wants to murder and has murdered gays, and they enslave women,' Trump said.

EARLY ADOPTER: North Carolinians stood in line all afternoon to hear Trump, including this teen who came dressed for the occasion

'THE KING' BACKS 'THE DONALD': NASCAR racing legend Richard Petty embraced Trump onstage Tuesday night after the Republican presidential hopeful announced his endorsement

And he heaped scorn on Clinton and her husband, former President Bill Clinton, for accepting millions in donations to their family foundation from Saudi Arabia and other nations in the Middle East.

They collected '$25 million from certain countries – and much more than that when you add it up – that treat women horrendously, that kill gays,' he said, calling on them to return the money while shouts of 'USA! USA!' ramped up in intensity.

'Since 9/11 the United States has admitted more than a half-million immigrants from countries where being gay is punishable by death,' Trump claimed.

'Hillary Clinton – Crooked Hillary as we all know her, which she is – wants to increase these immigration numbers very, very substantially. She's no friend of women and she's no friend of LGBT Americans.'

'How can you be a friend when these countries are oppressive to LGBT, when they're oppressive to everybody?' he said, directing the crowd's attention once more to the Clinton Foundation's fundraising.

'How can you be a friend to women when you take money from people that enslave women?'

'And then women like Hillary better than Donald Trump?' he asked. 'I don't think so. I'll be honest. I don't think so.'

Trump drew wild applause before he began his speech by announcing the endorsement of NASCAR racing legend Richard Petty, who came on stage to be acknowledged but did not speak.

The rally was interrupted a handful of times by protesters, with Trump urging police and his supporters each time to be gentle with them.

Greensboro Police Department Deputy Chief Brian Cheek said after the rally that a total of 20 people were ejected from the event. Seven of them, he added, were rrested for trespassing when they refused to leave the premises.