SIOUX CITY, Iowa — Republican presidential nominee Donald Trump told some 4,300 supporters in a packed convention center that their state was a key to victory.

“In two days — can you believe this? — and we are going to win back the White House,” he said, to cheers. “And I want to thank the people of Iowa, so much. You have opened your hearts to me.”

Some had waited since 2:30 a.m. to see Trump — on a night when most people were catching up on sleep, thanks to the end of Daylight Savings Time.

After his introductory remarks, Trump launched into an attack on Obamacare, which has been his major theme for the past two weeks.

He added that there was “more than enough evidence to garner indictments” against Hillary Clinton, “despite her efforts to disparage the FBI.”

He added that Wikileaks had revealed that Clinton had been “sending highly classified information through her maid.”

And he warned, as he has done for a week, that electing Clinton would lead to “an unprecedented constitutional crisis.”

He said the choice in 2016 was about “whether we will be governed by the people, or that corrupt political class.”

He added, to applause: “If we win, our country will start winning again.”

He also promised to “save” and “protect” Social Security: “You made a deal a long time ago.”

Trump said that “the media and the political elite” didn’t understand the pain of ordinary Americans, but that in running for president, he had learned about the reality.

He had gone, he said, from “a true insider” to “the ultimate outsider.”

“I’m not a politician. You, the American people, are my only special interest.”

He said that supporters of Sen. Bernie Sanders (I-VT) were coming over to his side, largely because of trade.

“He made a deal with the devil,” Trump said.

Trump also talked about agriculture, supporting corn-based ethanol.

“We will protect our family farms like no one has ever been protected before,” he said.

Trump promised to cut back regulations, especially Environmental Protection Agency regulations, which he said were even more damaging than taxes to small businesses.

“And, yes, we will build a Great Wall,” he said, to cheers, adding that Mexico would pay for it.

He also said Americans were tired of fruitless wars to defend foreign countries.

“But the politicians refuse to defend our borders,” he said.

“That will change in November 8th. A trump administration will never put the interests of a foreign country ahead of our country. From now on, it’s going to be ‘America First.'”

Linda Massey, a small business owner from Sioux City, told Breitbart News that she was hoping to see a “presidential” Trump onstage.

Her main reason for supporting Trump was her desire to see lower taxes, she said.She added that she had no doubt he would win Iowa. “No one I know is voting for Hillary.”

The entire Hertenstein family turned out to the convention center to see their first political rally.

Father Ben Hertenstein said he was “not 100% yet” with Trump. He wanted to see the “positive” case for Trump’s candidacy.

Josh Koenigs and Brian Scott of nearby Mapleton had original shirts made for the occasion, playing off the theme song of the movie Team America: World Police. The shirts read: “America: Trump Yeah!”

They were bullish on Trump’s chances on Tuesday. “I think he’s gonna surprise a lot of people,” Koenigs said.

A group of voters standing nearby said: “Amen!” One of them Jo Fuhrman of nearby Burbank, South Dakota, said that she had liked Trump from the moment she heard him on television. She felt the opposite about Hillary Clinton, who she said offered “nothing” to her. “Someday there should be a woman president — not that one,” Fuhrman said.

Teresa Wendel, part of a farming family based in nearby Schaller, came to the rally in mid-harvest season to hear Trump speak. She told Breitbart News that her Obamacare premiums had risen $4000 for the year. “I’m a farmer — where are we supposed to get the money?”

Sen. Joni Ernst (R-IA), a military veteran and the state’s first female U.S. senator, warmed up the crowd.

“Donald Trump gave a voice to millions of Americans,” Ernst said. “That is what we need in this election…someone who will listen to your concerns.”

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. His new book, See No Evil: 19 Hard Truths the Left Can’t Handle, is available from Regnery through Amazon. Follow him on Twitter at @joelpollak.