At Saturday's Freedom Summit in Manchester, N.H., Donald Trump talked about Obamacare, foreign policy, immigration and the economy, and he earned cheers and much applause from the audience.

Donald Trump at an event in April 2013 in Washington. (Jeffrey MacMillan )

The event, organized by Americans for Prosperity and Citizens United, attracted a crowd of conservatives and tea party members from New Hampshire. They came out to hear potential 2016 Republican presidential candidates like Sens. Ted Cruz (Tex.) and Rand Paul (Ky.) and many other GOP  politicians and pundits.

Trump called Obamacare "the single greatest lie I've ever seen in politics." He also spoke about Health and Human Services Secretary Kathleen Sebelius' resignation speech on Friday. She had misplaced a page of her speech, which he called "emblematic of all of Obamacare."

If a Republican had done that, Trump said, they would be labeled the stupidest person alive. "With her they said, 'Oh isn't that cute, she lost a page.'"

When Trump mentioned former Florida governor Jeb Bush, who has been mentioned as a possible moderate Republican presidential candidate, the audience loudly booed and groaned. The boos crescendoed when he mentioned Bush's comment that people who illegally immigrated to the United States may have “broke the law, but it’s not a felony. It’s an act of love.

Trump went on to extensively criticize Bush for his immigration stance.

Trump also blasted Rep. Paul Ryan (R-Wis.). He said Ryan "is a very nice person" but that Ryan is trying to dismantle Medicare.

Ryan's 2014 budget proposal has a plan to change the Medicare system in a way to advance government cost cutting. Trump is opposed to changing Medicare and said many Republicans agree with him on this point, even if they don't know it.

When Trump entered the room, he was greeted with a standing ovation. He also mentioned his admiration of the tea party, which he said "loves [him]."

He was introduced as the only person who could tell the president, "You're fired." Trump later admonished Obama as someone who "doesn't fire people. He never fires people."

When Trump moved his conversation beyond America's shores, he devoted a bit of time to Russia and its president, Vladimir Putin. "Russia, they are really hot stuff right now, Trump said. "What [Putin has] done for Russia is really amazing, and he's done it by outsmarting our country at every turn."

Economically, he said, other countries are "just kicking our ass."