"USA, USA, USA," roared about 1500 Americans when the US President told them he was bringing manufacturing jobs back to their country.

The gathering in a cavernous building in regional Ohio was meant to be a factory opening but it exploded into a Trump political rally as soon as he took the stage. Trump's people welcomed him to the state that helped him triumph at the last presidential election and could do it again next year.

Prime Minister Scott Morrison, standing with Trump, was suddenly face to face with a frenzied political force unlike anything an Australian election can produce.

The fumes from pulp paper wafted around the recycled paper and packaging factory at times. This was businessman Anthony Pratt's newest project, said to cost $500 million and backed by state loans to help Pratt and his company, Visy Industries, make a profit.

Pratt, an Australian who has become one of Trump's strongest supporters, brought the President and the Prime Minister together at an event timed perfectly for Morrison's official state visit to Washington DC.

Trump praised Morrison even more than he had last Friday when the two men met in the White House.

"I want to thank Prime Minister Morrison for being my friend - he's been a great friend to the United States of America. He's a great man and a great leader," said the President.

That was enough for the crowd. Sure that Morrison was their kind of leader, they cheered him on and laughed when he jokingly mispronounced their home town's name.

Trump may be waging a trade war with China that has triggered retaliatory tariffs on farmers. Trump may be hurting some farmers by cutting support for ethanol. But that is not enough to turn believers into waverers.

"We might struggle for a little while," said Mike Schaub, a soybean farmer who lives a few kilometres out of Wapakoneta.

"I think it will be good in the long run as soon we get things even. I'm 52 years old and the growth of the economy is the best I've ever seen, so I'm real happy."

Schaub said he wanted Trump to win next year to keep the Democrats out of power.

"They want to get rid of fossil fuels and guns," he said. "But there's no way they can get rid of fossil fuels - that would bankrupt our country."

His wife, Judy, was just as loyal.

"He's creating jobs, he's trying to close the border and build the wall and fix immigration," she said of Trump. "He's proven himself. And he's not a politician - he's a businessman."

This was the key feature of Trump's appeal - and Morrison had a rare opportunity to see how it could turn politics-as-usual into pulp.

The energy was extraordinary as the crowd responded to Trump's call to "make American great again" and laughed at his jokes, even when a joke was about lower wages. Perhaps they were helped by the thundering music before the performance. Macho Man, by YMCA, seemed a telling choice.

Morrison may be assuming a Trump victory is more likely than not next year. Certainly his appearance on stage may be awkward to explain if a Democrat takes the presidency.

For some Australians, Morrison was no doubt too close for comfort to Trump, a figure who is divisive in Australia just as he is in his home country.

But Morrison was also close enough to watch and learn. This was an expert demonstration of retail politics at a professional level unlike the Australian experience.

With a small irony, it ended with You Can't Always Get What You Want by The Rolling Stones, even though the event had everything a politician could hope for.

Whether Morrison returns home with any tips from the Trump campaign machine is a live question.

One lesson stood out. The very thing Trump critics lampoon - the wild talk that is so different to any standard politician - can be the very reason others respond to his message.

"You feel like you see him for what he is," said Ashley Doty, an office worker. "You don't feel you're seeing some face that he puts on when he stands up on the podium.

"I think what he's doing is what he believes is the best thing for America and it's what you don't get from most other politicians. He's not just doing it for a pay cheque."