With several of his Democratic rivals hosting competing events down the street, President Trump confidently told raucous rallygoers Thursday evening in New Hampshire, the state that gave him his first presidential primary win, that they have "no choice" but to vote for him again in 2020 -- if they want their 401(k)s to remain intact.

"Are we sure we're in New Hampshire?" Trump asked at one point, as the crowd roared and he discussed the state's soaring economy. "You have a reputation as a very staid, very elegant people, and you're not acting it tonight, and that's a good thing."

And after a protester briefly interrupted the rally, Trump remarked, "That guy has a serious weight problem. Go home, start exercising. Get him outta here."

It emerged on Friday that Trump had confused one of his own supporters for the protester -- but the Trump fan told Fox News he "still loves" the president, even after he called out his "weight problem."

When the sparks died down at the rally, Trump turned to domestic and foreign policy, with a focus on the economy. Responding to recent mass shootings in Texas and Ohio, the president emphasized the importance of mental health treatment and vowed, to sustained applause, "We will always uphold the Second Amendment."

Trump also promised to work more on the opioid epidemic, which, according to The Washington Post, has claimed more lives in 2017 alone than mass shootings have in the past five decades.

"Now we have a bunch of socialists or communists to beat."
— President Trump

"We have reduced the total amount of opioids prescribed by 34 percent," Trump said, noting that thousands of defendants have been prosecuted federally in opioid-related cases.

A fiery stage was set hours before Thursday's rally, when the president told reporters at a New Jersey airport that Reps. Ilhan Omar, D-Minn., and Rashida Tlaib, D-Mich., were "very anti-Jewish and anti-Israel" -- and said he supported Israel's decision to bar them from entering the country.

"Now we have a bunch of socialists or communists to beat," Trump said, as the Manchester crowd jeered. "They're not far away. Does anybody want to pay a 95-percent tax?"

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Trump went on to say that recent episodes in which people threw water on New York City police officers were indicative of a larger trend among progressives.

Supporters cheering at President Trump's campaign rally on Thursday. (AP Photo/Elise Amendola)

"They view everybody as fascists and Nazis ... They accuse our heroic border agents of running concentration camps," Trump said, in an apparent reference to New York Rep. Alexandria Ocasio-Cortez. "And, they look down upon the hardworking citizens who truly make our country run."

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Less than a month ago, Trump supporters in North Carolina erupted in a chant of "send her back" directed at Omar as Trump spoke, prompting the president to urge future rallygoers not to use that language. At a later rally, Trump avoided mentioning Omar by name -- but, on Thursday, he directly named her and other members of the so-called progressive congressional "Squad."

The president was making the quick trip to Southern New Hampshire University as he spends the week at his New Jersey golf club. The event gave Trump a chance to address the heightened fears about the economy, fueled by a development in the bond market that had predicted previous recessions.

Avoiding an economic slump would be critical to Trump's reelection hopes.

During the rally, Trump talked up the economy extensively. "We've created over 6 million new jobs since the election," Trump said, adding that more than 7 million Americans "have been lifted off food stamps."

"America is working again, America is winning again -- and America is respected again, like never before," Trump said.

A nearly full house roared its approval throughout the speech. Trump campaign manager Brad Parscale told Fox News there were roughly 12,000 in attendance at the Southern New Hampshire University Arena. A handful of rows of empty seats were visible mid-rally in the uppermost seating areas.

Trump added that China was "eating" the cost of his tariffs, and losing scores of jobs amid the ongoing trade war.

"We had a couple of bad days, but we're going to have some very good days 'cause we had to take on China," Trump said. "I never said China was gonna be easy. ... And again, China's devaluing their currency, they're pouring at money, the prices haven't gone up -- so that means we're taking in" money.

The markets in the early afternoon had clawed back some of their steep losses from the previous day. Trump told rallygoers that the markets would have "crashed" entirely if he were not president, and that they should focus on the big picture, rather than short-term losses.

"You have no choice but to vote for me," Trump said. "Your 401(k)'s gonna be down the tubes" otherwise.

He continued: "Whether you like me or hate me, you've got to vote for me."

The crowd at the Southern New Hampshire University Arena on Thursday. (Fox News' Paul Steinhauser)

Trump also criticized Democrats for supporting late-term abortions, saying the governor of Virginia, Ralph Northam, had endorsed "executing" infants post-birth.

“The infant would be delivered," Northam said in a radio interview earlier this year. "The infant would be kept comfortable. The infant would be resuscitated if that’s what the mother and the family desired, and then a discussion would ensue between the physicians and the mother."

He also said his administration will have appointed nearly 200 federal court judges by the end of the year.

New Hampshire, which Trump lost by about 2,700 votes in the 2016 general election, has been doing very well economically. According to June government figures, New Hampshire had the fourth-lowest jobless rate in the country.

"You have the most successful state in the history of your state, and the history of our country, and you're gonna vote for somebody else?" Trump asked sarcastically. "We have the best numbers we've ever had. Let's vote for somebody else! I don't think that's gonna happen. Only with fixed polls is that gonna happen."

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Despite the rosy numbers, a recent poll from the University of New Hampshire Survey Center poll found 42 percent of New Hampshire adults approved of Trump while 53 percent disapproved. The poll also showed 49 percent approved of Trump's handling of the economy and 44 percent disapproved.

And, a national Fox News poll released Thursday showed Trump trailing Joe Biden by 12 points (50-38 percent), Bernie Sanders by 9 (48-39), and Elizabeth Warren by 7 (46-39). Those leads were outside the poll’s margin of error. It was the first Fox News Poll to show a lead for Warren outside the margin of error.

"I saw some fake polls put out by the fake news media," Trump said in New Hampshire, as the crowd booed. "We have taken this big, beautiful ship, and it's being turned around -- very quickly."

Some Democrats' presidential campaigns were holding events to capitalize on Trump's trip. Biden's campaign set up down the street from the arena to talk to voters and enlist volunteers.

Responding to reports that Biden was considering scaling back campaign events because of his frequent gaffes, Trump called the former vice president a "disaster" and repeated a frequent attack, labeling his rival "Sleepy Joe Biden."

As Trump spoke, a group for Pete Buttigieg's campaign gathered in nearby Concord to call voters about his support for new gun safety laws.

And, Cory Booker urged Trump to cancel the speech and instead urge Congress to take immediate action to prevent gun violence.

How New Hampshire receives the president on Thursday likely will offer a fresh test of whether voters will give credit to Trump for the state's economy in 2020.

At 2.4 percent, New Hampshire's seasonally adjusted unemployment rate for May was among the lowest in the nation. But, wage growth was significantly below national gains. Average hourly earnings rose a scant 1.1 percent in New Hampshire in 2018, lagging the 3-percent gain nationwide, according to the Bureau of Labor Statistics.

In other ways, like the homeownership rate — first in the nation — and median household income — seventh in the U.S. — the state has been thriving, according to census data.

New Hampshire's four Electoral College votes are far fewer than what key swing states such as Florida, Wisconsin and Michigan would provide, but its influence has proven powerful in close election years such as 2000, when George W. Bush's victory in the state gave him the edge needed to win the White House.

Meanwhile, Trump on Thursday threw his support behind his former campaign manager, Corey Lewandowski, who has been considering a run for Senate in his home state of New Hampshire.

Trump praised Lewandowski as "a very outstanding guy" in the "New Hampshire Today" interview. Trump said he thought Lewandowski would be hard to beat if he decided to challenge Sen. Jeanne Shaheen, a Democrat.

At Thursday's rally, Trump touted Lewandowski as "tough" and "smart," and predicted he would be "tough to beat" in the Senate. But, the president noted Lewandowski was still mulling a run.

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"Corey, let us know please, if you don't mind," Trump said.

The comments came hours before the House Judiciary Committee announced it was subpoenaing Lewandowski and an ex-White House aide as part of its investigation into Trump's conduct in office. Lewandowski responded in a tweet writing that it was "sad and pathetic" that the committee's chairman, Rep. Jerry Nadler, D-N.Y., "is harassing private citizens."

Fox News' Paul Steinhauser in Manchester, Dana Blanton, Andrew O'Reilly and The Associated Press contributed to this report.