Republican presidential candidate Donald Trump headlined a rally at New York's Madison Square Garden on Sunday that began with a series of vulgar and racist remarks by allies of the former president.

Trump, a New York celebrity for decades, hoped to use the event at the iconic venue known for Knicks basketball games and Billy Joel concerts to deliver his closing argument against Democratic candidate Kamala Harris, even though the state last backed a Republican presidential candidate in 1984.

Trump spoke repeatedly about his plans to halt illegal immigration and deport migrants he described as "vicious and bloodthirsty criminals" if he wins the Nov. 5 election.

"On day one I will launch the largest deportation program in American history," he said. "I will rescue every city and town that has been invaded and conquered."

Trump called Harris a "very low IQ individual" and drew cheers from supporters for his tough-on-migrants rhetoric.

He vowed to ban sanctuary cities, which refuse to cooperate with the federal government in enforcing immigration laws, and to invoke the 1798 Alien Enemies Act law to deport immigrants with criminal records.

A long list of opening speakers varied widely from former pro wrestler Hulk Hogan to former New York City Mayor Rudy Giuliani to Trump’s sons Eric and Don Jr.

Some used racist and misogynistic language in warming up a capacity crowd.

Giuliani, a former personal lawyer to Trump, falsely claimed that Harris was "on the side of the terrorists" in the Israeli-Palestinian conflict.

Comedian Tony Hinchcliffe used crass language in joking that Latinos "love making babies" and called the Caribbean U.S. territory of Puerto Rico a "floating island of garbage."

Puerto Rican singer Ricky Martin posted a clip of the comments on his Instagram and wrote, in Spanish, "This is what they think of us."

Danielle Alvarez, a senior adviser to the Trump campaign, told Reuters that the joke about Puerto Rico "does not reflect the views of President Trump or the campaign."

While Puerto Ricans are U.S. citizens, residents of the island cannot vote in U.S. general elections.

However, millions of Puerto Ricans who have moved to the mainland United States can vote, and there is a large community in the battleground state of Pennsylvania.

Harris earlier on Sunday visited a Puerto Rican restaurant in Philadelphia, the largest city in Pennsylvania. She posted a video on social media promising to "invest in Puerto Rico's future" as president.

Harris's campaign in an email said the Madison Square Garden rally was "mirroring the same dangerously divisive and demeaning message" as Trump.

Trump's 2016 presidential opponent, Democrat Hillary Clinton, has accused him of "re-enacting" a pro-Nazi rally that was held at Madison Square Garden in 1939 on the eve of World War Two.

Trump’s critics have long accused him of empowering white supremacists with dehumanizing and racist rhetoric.

Trump rejected the comparison to the 1930s. "This is called Make America Great Again, that's all this is," he said on Friday.

“Today this is Donald Trump’s house,” wrestler Hulk Hogan said at the New York event on Sunday. He rejected accusations that Trump is a fascist: “I don’t see any Nazis in here."

U.S. billionaire Elon Musk, who is supporting Trump's reelection bid with his X social media platform and enormous wealth , was greeted to the stage with chants of "Elon."

“This is the kind of positive energy that America is all about,” Musk said.

Musk, who Trump has said he would tap to lead a new government efficiency commission, said the federal budget could be reduced by "at least" $2 trillion.

Discretionary spending, including defense spending, is estimated to total $1.9 trillion out of $6.75 trillion in total federal outlays for fiscal 2024, according to the Congressional Budget Office.

Trump in his speech argued that Americans are worse off now than four years ago.

He announced a new policy to provide a tax credit for caregivers who take care of a parent or another family member.

Trump touted his foreign policy record during his 2017-21 presidency, and said he would not start wars in office, though he added that if the United States did have a war with China, "We would kick their ass."

Polls show Harris and Trump neck and neck in the battleground states that will decide the next president with just over a week until Election Day. More than 38 million votes have already been cast across the country.

Trump has sought to tie Harris to the Biden administration's handling of immigration and the economy. Last week, Trump debuted a new attack line: "She broke it, and I promise you I will fix it."

The economy has outperformed the rest of the developed world since the COVID crisis, and stock markets hit record highs this year. But high prices of food, utilities and housing have roiled voters, who believe the economy is headed in the wrong direction.

Harris, who held a rally with Bruce Springsteen in Atlanta on Thursday and with Beyonce in Houston on Friday, will hold another high-profile event with a speech on Tuesday on the National Mall in Washington, where she will highlight the differences between herself and Trump.

"He is full of grievance. He is full of dark language that is about retribution and revenge," Harris said of Trump in Philadelphia on Sunday.

Trump's campaign said the event at the 19,500-seat Madison Square Garden, which can cost upwards of $1 million to rent, was sold out. Tickets are free and on a first-come-first-served basis, as was the case with Harris' Houston rally.

A crowd of some 30,000 people attended Harris' rally with Beyonce on Friday night in Houston, and about 20,000 attended the Atlanta rally.

"My internal polling is my instinct," Harris said to reporters in Philadelphia when asked how the campaign is faring in its internal election projections. "The momentum is with us,"