MANHEIM -- The most coveted groups of voters in Pennsylvania and across the country are African-Americans and millennials.

When Donald Trump showed up more than an hour late to a Lancaster County campaign stop, he focused on the latter.

Millennials make up 19 percent of eligible voters, and the majority of those voters chose Bernie Sanders during the primary election.

There didn't seem to be one Sanders supporter in the crowd of more than 6,000 people, but Trump wasn't talking to the people inside the Spooky Nook Sports Complex. He was looking into the sea of cameras in the back.

Though the primary election is long over and Sanders has shown strong support for Democratic presidential nominee Hillary Clinton, Trump pit the two against each other.

Sanders was on one side, opposing trade deals and fighting for millennials. Clinton was on the other side, calling the Trans-Pacific Partnership the "gold standard" and mocking Sanders, according to Trump.

"One man knew the dangers of TPP - Bernie Sanders," Trump said. "He knew we were being ripped off and was going to do a lot about it."

Trump used it as a platform from which to jump into his familiar promise to bring back jobs and stop TPP.

"If we don't stop it, billions and billions of jobs and wealth will be vacuumed out of Pennsylvania," Trump said. "Together we will stop TPP and we can end the theft of American jobs and prosperity."

The Republican presidential nominee wooed the crowd with promises to return a bygone era, one in which Pennsylvania steel will again build skyscrapers like the Empire State Building.

"It's time we take our country back and act like intelligent people," Trump said. "We are going to protect our miners. We are going to protect our steelworkers."

Clinton, he said, knows nothing about jobs.

"She's an incompetent woman," Trump said. "Her run for the presidency will never ever work out because we can't let it work out."

At various points, the crowd erupted into chants of "Lock her up!" and Trump said she belongs in prison.

Some of the people there shouted "Benghazi!" during Trump's speech.

But the Republican nominee focused more on his continuing theme of a crumbling America only he can save.

Trump will save it from Mexico, China, special interests and, especially, the woman running against him.

"With Mexico, we get the drugs, they get the cash," Trump said. "By the way, we're going to have a very, very powerful, very strong southern border."

The crowd offered its most vigorous applause and yelled, "Build that wall!"

Trump, as if on cue, asked who was going to pay for the wall.

"Mexico," the crowd shouted in unison.

Trump quickly said, "100 percent. They may not know it yet, but they're paying for it."

The only thing standing between him and "the wall" is a corrupt election in Pennsylvania.

Trump renewed his claim that if he loses Pennsylvania, it's because of corruption.

"Watch the polling booths because I hear too many bad stories about Pennsylvania," Trump said Saturday night. "And we can't lose an election because you know what I'm talking about."

When Trump campaigned Aug. 12 in Altoona, he said the only way he would lose the state is if cheating occurs.

Trump on Saturday night asked the crowd to watch the polls.

"Go over and watch and watch carefully," Trump said, "because we're going to win Pennsylvania. And if we win Pennsylvania, we take back the White House."

Trump did not say which areas of Pennsylvania he was concerned about or where people should watch the polls.

The Republican nominee took many detours in his speech, suggesting Clinton is cheating on her husband, saying numerous U.S. cities are worse than war zones and again calling on African-Americans to vote for him because "What do you have to lose?"

However, he ultimately came back to the campaign slogan that launched what he describes as "a movement."

"If we don't win, I don't care what they write, I will consider it a tremendous waste of time, energy and money," Trump said. "If we don't get there, we won't be able to do the job."

Trump promised if he is elected, Americans will be "so proud of your country once again."

"The world looks at us like we're stupid people, but we're not going to be stupid much longer," Trump said.

And he closed with his signature line, made famous after he rode down the Trump Tower escalator in June 2015 and announced his candidacy: "We're going to make America great again."