(AP Photo/John Locher) Republican presidential candidate Donald Trump speaks at FreedomFest, Saturday, July 11, 2015, in Las Vegas.

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."

(MSNBC/screenshot)

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."

(AP Photo/John Locher)) Republican presidential candidate Donald Trump speaks at FreedomFest, Saturday, July 11, 2015, in Las Vegas.

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.