Donald Trump took his first serious notice of Bernie Sanders on the campaign trail on Friday night, telling a crowd of more than 11,000 people in Tampa, Florida that the Vermont senator is 'a communist.'

The Republican presidential front-runner never named Sanders, the self-described democratic socialist who is giving former secretary of state Hillary Clinton fits and starts in the Democratic primary fight.

But there's no mistaking who The Donald meant.

'I'd love to run against her,' he said of Clinton. 'I'd also love to run against the communist.'

IN ALL HIS GLORY: Donald Trump spoke to more than 11,000 people at the University of Southern Florida's Sun Dome on Friday night

IT'LL PROBABLY WASH OFF: These six first-time voters wore body paint and yelled to attract The Donald's attention

YUUUGE CROWD: More than 5,000 people packed the floor area at the Sun Dome, standing cheek-to-jowl while Trump spoke

'I never thought we'd see the day in our country,' he said, 'when a communist – because that's really, if you think about it – when a communist is the leading Democrat!'

'We're going to have a communist against the entrepreneur. I like the entrepreneur. Don't you think?'

'I watch this great country, and if that's the best we can do, that's pretty sad when you think of it. It's pretty sad,' Trump said.

Trump took aim at his Republican challengers too, making a fast-asleep motion with his hands together like a pillow under his head at the first mention of former Florida Gov. Jeb Bush

'He's asleep. He's asleep at the wheel, folks,' Trump said.

The billionaire has branded Bush a 'low-energy' candidate in the past, and one of the songs in his pre-rally playlist is thought to be a jab at the Floridian.

The heroic aria, 'Nessun Dorma' from the Puccini opera 'Turandot,' includes Italian lyrics that translate to 'No one shall sleep' and "I will win.'

Trump railed against 'special interests' and 'lobbyists' whom he said have poured more than $148 million into Bush's campaign and super PACs supporting him, resulting in 'phony ads' running in South Carolina this week.

ANGRY ENTREPRENEUR: Trump said Bernie Sanders is a 'communist' and it was 'very sad' to see one as a potential Democratic Party nominee

DIGITAL CAMPAIGNING: Thousands of Floridians strained to get a souvenir picture of Trump as he entered the arena

CARNIVAL: Trump's supporters brought signs of all kinds

FAMILY AFFAIR: Grace Hill, 8, and Ella Hill, 5, stood with their parents as they waited for the start of Trump's rally. The girls were later seen sitting atop their mother and father's shoulders

'He's nothing anyway. He's not gonna go anywhere,' Trump said of Bush. 'But without that [money] he would have failed months ago. It's the only thing he's got.'

'In his own way he's a vicious guy,' he said of Bush. 'You know, he's got that little vicious streak. Because he's a gutless guy.'

Jeb, he said, has bought '$20 million worth of negative ads on Trump! What the hell did I do to him?'

The Tampa rally, sandwiched between Thursday night's record-setting crowd in Baton Rouge, Louisiana and a debate Saturday night in Greenville, South Carolina, was vintage Donald.

Rally-goers saw a carnival atmosphere including organized contingents of 'Christian bikers for Trump' and a woman holding a four-foot-tall playing card – a 'Trump card' – with the candidate's face superimposed on a giant King of Hearts.

The University of Southern Florida's Sun Dome, was packed to the rafters. Its seating areas can hold about 10,500 people, but an arena official said there were nearly 6,000 more standing on the floor.

Fans in the arena's seats started 'the wave' a half-hour before Trump came out, as paper airplanes flew in the air and children sat on parents' shoulders.

In the upper deck, six shirtless young men sported giant red letters painted on their torso, spelling the name T-R-U-M-P – plus an exclamation point.

'People started lining up 7 hours ago!' Trump told them when he entered. 'This is a movement.'

He claimed to have 'thousands and thousands of people outside' who couldn't get in. 'We have screens set up for them outside!'

OVERBOARD? One woman at Trump's rally ranked him above 'God' and 'Jesus'

BIKERS FOR TRUMP: The Donald has attracted a wide range of Americans who feel ignored and disaffected by career politicians

'BUILD THAT WALL!': Rally-goers erupted in that chant several times on Friday night, led by a group of college-age young men who walked through the crowd and shouted the slogan

Clinton, who was campaigning Friday in Minnesota, made an unexpected appearance in Trump's stream-of-consciousness when a man in his audience shouted her name as he castigated the Chinese air force for making a knock-off version of a U.S. military plane.

'They copied the F-35 plane, the fighter, right? You can't tell the difference,' he said.

'You look at it. They copied our plans. And they did more than copy our plans. I guarantee you they have everything they need right down to the most complicated mathematical solutions. All done. 100 per cent. Stolen off our web.'

And then a voice rang out: 'Hillary gave it to them!'

'Yeah, maybe it was stolen from her emails!' Trump said in a theatrical eureka moment. 'That's what happened!'

'Maybe it was stolen from her emails!' he crowed.

'I don't know if Hillary's going to get a chance to win' the Democratic nomination, Trump said later.

'By the way, I'm beating her in the polls. Beating her. I will beat her.