Republican presidential candidate Donald Trump speaks at FreedomFest, Saturday, July 11, 2015, in Las Vegas. AP Photo/John Locher Donald Trump just gave one of the most bizarrely captivating speeches of his several-weeks-old campaign.

Standing in front of an animated screen in Las Vegas on Saturday, Trump spoke passionately for almost a half an hour, hitting some of his main talking points: President Barack Obama's weakness, a 'porous' southern border, his business successes, and even Benghazi.

It was one of two similarly themed speeches in the day. Later, he spoke before a crowd of what his campaign said was more than 15,000 in Phoenix.

Trump made illegal immigration the primary focus of both speeches, railing against the Mexican government for supposedly sending undocumented immigrants to the US.

Trump faced widespread criticism after he said in his announcement speech last month that some Mexican immigrants are rapists and drug dealers. But he refused to back down from his comments about the danger of undocumented immigrants.

"They're sending us their problems," Trump said in Las Vegas, referring to Mexico.

To illustrate his point, Trump brought a man onstage named Jameil Shaw, whose son was killed in 2008 in the Los Angeles area. The killer, Pedro Espinoza, was a gang member and an undocumented immigrant. Espinoza was sentenced to death in 2012.

Trump said that as soon as authorities realized that Shaw's son was shot by an undocumented immigrant, "nobody wanted to talk about it."

Trump proposed that protesters and critics were being sent by the government of Mexico to oppose him.

"They were so sophisticated. I guarantee you that the country of Mexico had those people [sent there]," Trump said.

Trump mocked media outlets for doubting his self-proclaimed $9 billion fortune, proof of which the real-estate mogul claims that he will release next week.

"I'm much, much richer than what they say," Trump said. "I'm a private person, nobody knows."

Republican presidential candidate Donald Trump speaks at FreedomFest, Saturday, July 11, 2015, in Las Vegas. AP Photo/John Locher) Trump praised various Republican constituencies, including Tea Party voters and libertarians.

"Nobody knows the power of the Tea Party. I only say that because the Tea Party loves me," Trump said.

Since Trump's speech, numerous companies with business connections with Trump including NBC, Macy's, and Nascar announced that they would be cutting ties with the reality-television star.

In the speech on Saturday, Trump again singled out Univision for its decision to not to carry Trump's Miss USA pageant, suggesting that Mexico itself pressured Univision to sever ties with Trump.

"Mexico put the clamps on Univision," Trump said. "Mexico has a lot of power over them."

Trump also blasted the Obama administration's negotiating skills, slamming the administration's agreement to exchange five Guantanamo Bay prisoners for Sgt. Bowe Bergdahl, who was being held hostage by the Taliban in Afghanistan in June 2014.

"Here's a guy, Sergeant Bergdahl. We get Bergdahl, a traitor, a no-good traitor, who in the good old days would've been executed, and they get five killers who are right now out on the battlefield," Trump said.

According to the New York Post, three of the five former detainees traded for Bergdahl have attempted to contact associates within terrorist networks.

Trump touted his strength at making deals, citing his book, "The Art of the Deal," as a reason why he should be put in charge of trade deals and nuclear negotiations.

"You know who hasn't read [the Art of the Deal]? Obama," Trump said.

He also opined on the ongoing negotiations over Iran's nuclear program.

"Persians are great negotiators, Iran great negotiators," Trump said.

Most of Trump's solutions relied heavily on Trump's personal deal-making skills and were not particularly specific, but the reality-television star did have specific idea in mind: Put hotel mogul Phil Ruffin in charge of deal-making with China.

Toward the end of the speech, Trump brought Ruffin onstage to highlight how a good deal is made.

Trump currently leads the Republican field in several polls taken of likely GOP primary voters nationally and in primary states like North Carolina.

According to Public Policy Polling, Trump has a slight lead over former Florida Gov. Jeb Bush (R) in North Carolina, with 16% of Republican primary voters supporting the real-estate magnate.

Though many pollsters and analysts have been quick to write off Trump's campaign, his speech on Saturday played to what primary voters love about Trump: his candor, bombast, and unwillingness to concede defeat.

When confronted by a questioner who criticized Trump's comments about Mexico, the reality-television star sighed and said, "I was waiting for this."

"Did the government of Mexico ask you to come here?" Trump asked, talking over the questioner.

Right-leaning campaign strategist Liz Mair and the Potomac Group's Greg Valliere both told Business Insider last week that Trump appealed to a part of the electorate that appreciates the real-estate mogul's willingness to say what other candidates would not.

"He has supporters who hate the status quo, who like someone who says what people are thinking but won't discuss publicly," Valliere said.