The state's corporate community last week finally got around to blasting the immigration plan of presidential candidate Donald Trump, through an essay on the Star Tribune's commentary page by the Minnesota Business Partnership's Charlie Weaver.

Weaver, the group's executive director, called Trump's plan "unworkable, hugely expensive and harmful to American employers and workers."

It was a good start, but Weaver didn't go nearly far enough. What Trump seems to be up to is far worse than damaging the U.S. economy. Trump seems intent on wrecking a part of the entrepreneurial culture that's at the very core of our identity as Americans.

That was one of the ironies of the summer of Trump, watching an insurgent campaign to "Make America Great Again!" relentlessly go after one of our greatest strengths.

The New York businessman and reality TV star, whose career has invited comparison to the great P.T. Barnum's, has made immigration policy such a big part of his campaign that there's still nothing else on the "positions" page of his campaign's website.

He's proposed, and never mind the practicality, things like getting Mexico to pay for a new wall along our common border.

GOP presidential candidate Donald Trump has made immigration a key piece of his campaign.

He also has insisted on ending automatic citizenship for children born here, no matter the origin of their parents, as spelled out in the 14th Amendment to the Constitution. We've enjoyed 239 years of raucous electoral politics in this country, but as best as can be determined Trump is the first leading candidate for president of the United States who has called part of our own Constitution unconstitutional.

Trump's anti-immigrant message has found a receptive audience among likely Republican primary voters. Earlier this year the Pew Research Center found that nearly two-thirds of Republicans said immigrants are a burden to the country by taking jobs, housing and health care, not an asset that strengthens it through their hard work.

So it's no surprise that other Republican presidential candidates have piled on when it comes to ending so-called birthright citizenship, giving the impression that it's a terrible problem that pregnant tourists stay over long enough to give birth to an American.

The reality is that what brings people here, and it's long been the case, isn't a chance at a fortuitous birth. It's economic opportunity. It's the chance to accomplish something in business that isn't possible back home.

There's plenty of evidence to support this conclusion. Earlier this year a study put out by the Americas Society/Council of the Americas and the Fiscal Policy Institute found that between 2000 and 2013, immigrants were responsible for all of the net growth in so-called Main Street businesses.

By 2013 immigrants owned 61 percent of the country's gas stations and 53 percent of its grocery stores. They owned well over one-third of the restaurants.

Here in the Twin Cities foreign-born people made up less than 10 percent of the population, according to this analysis of census data, but they owned more than 13 percent of Main Street businesses.

"That's one of the very interesting things, why not do the conventional thing and go into the labor force," said Paul Vaaler, professor at the Carlson School of Management at the University of Minnesota, who has studied immigrant entrepreneurship. "That is not specific to Somalis or Liberians. That was Vietnamese and Cambodians 40 years ago. It's Ethiopians 30 years ago. It's nothing new. It was Norwegians a hundred years ago."

Not many immigrants have a good job to give up for the risk of a storefront business, he explained. As for capital, they often can lean on both a broad network of extended family here as well as ties to their families still in the old country.

Not that getting any business going is easy, he added. Any start-up needs to overcome the inherent liability of being new, with no customers who trust the business. For immigrants there's the second liability of being seen as "foreign" when looking for their first customers.

That's why a lot of entrepreneurs get their start in what's called "enclave capitalism," an area made up of residents largely from the same home country, buying and selling with one another.

This concept goes back to the early research on the area of south Florida called Little Havana, where Cuban immigrants who went to work for other immigrants were found to have done much better financially than they would've had they sought jobs out in the broader economy. As for the Cuban-born entrepreneurs, they did even better, many eventually growing out of their enclave and serving a far broader market.

Is America still a beacon of light for hopeful immigrants willing to risk everything to start over in business?

"Absolutely," Vaaler said. "Why? Because contracts work. Because people keep their word here, and there's a rule of law. Because the notion of class and barriers that are often determined by gender or ethnicity are less apparent here."

Last week my colleague Adam Belz took readers into one of those booming pockets of enclave capitalism here in the Twin Cities, the Karmel Square mall in Minneapolis. It's the home to about 175 clothing shops, hair salons, restaurants and other shops established by Somali-born entrepreneurs.

He later described a trip that Karmel Square shop owner Amallina Ali took back to her native Africa, where it didn't take long for her to start missing her home in America. She wanted the good customer service she'd come to expect. She missed the rule of law.

"Why we are a superpower is the justice, equality," she said. "It does not exist anywhere. That's why we do well here. It might not be 100 percent, but we have the best on this planet."

And that, finally, is the most fundamental thing Trump has gotten dead wrong, every time he dons his cap that says "Make America Great Again."

Right now, Labor Day weekend of 2015, America is a great country.

If Trump remains confused about that, he should arrange a trip here and drop by Karmel Square. Our Somali-born CEOs would happily set him straight.

lee.schafer@startribune.com • 612-673-4302