Every conference needs a good troll. And Donald Trump seemed happy to play the part at CPAC with a rambling speech on Friday that ranged from the evils of immigration reform to an exhortation to re-invade Iraq.

Trump gave the first keynote of the second day of the biggest annual gathering of conservatives in the US. He used it run against the tide of Republican opinion on immigration, to call for the expropriation of Iraq's oil, and to complain that the Obama administration turned down his offer of building a ballroom in the White House grounds.

In what would have been a damaging revelation if it had come from a more credible source, Trump said "high-level officials" told him before the Iraq war that the US was "going for the oil". The trouble was, it didn't get any. Trump's remedy: go back for it.

Donald Trump on Iraq's oil reserve: "I say we should take it and pay ourselves back" #CPAC — Cameron Joseph (@cam_joseph) March 15, 2013

Trump's speech was greeted with polite applause, and there was a standing ovation from some parts of the room, but it did not electrify the GOP base in the way that Marco Rubio or Rand Paul had done a day earlier.

His solution for America's woes was that it needed to build a better economy, mostly through manufacturing televisons again. (A logic somewhat undermined by his revelation that he has just placed an order for 3,000 televisions with South Korea). "Our country is in very, very serious trouble," he said.

Going against the tide of opinion from the platorm at this year's CPAC conference, Trump warned against any embrace by the GOP of immigration reform: regularising the immigration status of "11 million illegals" would create 11 million Democrat voters, he said. The Republican party risked putting itself on a "suicide mission". Instead, he argued, the US should consider allowing more Europeans to the country.

Trump repeated a complaint that the White House wouldn't let him build one of his big tacky ballrooms on the back lawn. They wouldn't even call him back. "That's the problem with this country," he raged. "People don't get back to you."

He also launched into a big advert for his new golf resort in Florida, where he was hanging out with Tiger Woods earlier this week. (Admittedly, it sounded very nice.) This was the problem with Mitt Romney: he didn't go on about how wealthy he was, often enough, Trump says. 'If Mitt made one mistake, he didn't talk enough about his success.' Yes! That was it!