As the presidential campaign heats up so will the debate over the role of immigrants in our economy and our communities.

That has been an ongoing conversation in Lewiston-Auburn for the past 10 years and a hot-button topic in southwestern border states for decades.

But the controversy will likely get louder as Mitt Romney and Barack Obama debate two current subjects.

First, in 2010 the Arizona legislature passed the toughest anti-illegal immigrant law in the land.  Last week the U.S. Supreme Court upheld a controversial provision of the law allowing police officers to ask people for immigration status documentation.

But the court also struck down two other provisions allowing police to arrest and hold illegal immigrants and another section that would have prevented illegal immigrants from seeking jobs.

Second, the DREAM Act would give conditional permanent residency to people who arrived illegally in the U.S. as minors. They could eventually obtain citizenship by fulfilling certain military obligations or by obtaining a college degree.

To be clear, much of the upcoming debate will be over illegal immigration. Too often, however, many Americans seem hostile to immigrants in general.

Two recent reports, however, suggest immigrants will be critical to sustaining our economy as our native-born population ages.

The Fiscal Policy Institute, a New York State research group, reported June 14 that more than one sixth of small business owners in the U.S. were not born here.

The data is drawn from the 2010 Census and American Community Survey.

Those immigrant-owned small businesses, with fewer than 100 employees, employ 4.7 million Americans and had total receipts of $776 billion.

A host of studies have found that immigrant Americans are more likely to be entrepreneurs than native-born Americans and to seek Small Business Administration loans.  The SBA reports immigrants are twice as likely as native-born Americans to start a small business.

One study in 2008 found that half of Silicon Valley start-ups are founded by immigrants.

New arrivals from other lands are particularly over-represented in the high-growth industries requiring mastery of STEM subjects: science, technology, engineering and math.

What’s more, 76 percent of patents from America’s top universities have a foreign-born inventor.

While immigrants are over-represented in hard sciences, they are, as the study notes, “more likely to be found on Main Street than in a technology park.”

Thirty-seven percent of restaurant owners are immigrants, as are 49 percent of grocery store owners and 54 percent of laundry and dry cleaning firm owners.

That finding is reinforced by a broader report released in March by the Brookings Institute showing immigrants are clustered in both high-skill and low-skill jobs in our economy.

As more Americans obtain high school degrees, technical training and higher education, immigrants are filling jobs in agriculture, in manual labor and as maids and restaurant workers.

In 1994, 72 percent of American workers without a high school diploma were U.S.-born. By 2010, they made up just 48 percent, according to the Brookings report.

Immigrants fill nearly one in four jobs in information technology and high-tech manufacturing. On the other hand, they make up about half the workers in private households and in the accommodation industry.

Immigrants are also over-represented in health care, where they fill not only the most highly skilled positions as surgeons, but as hospital orderlies and laundry workers.

In most industries like construction, native-born Americans are more likely to serve as managers, supervisors and in skilled positions such as carpenters, plumbers and electricians.

Ninety-seven percent of farmers and ranchers are native-born, while 60 percent of their workers are not.

The important message in the statistics is clear and should not be confused in the upcoming debate.

As our native-born population ages, and as the U.S. birth rate declines, our economic self-interest depends upon welcoming young, ambitious, talented students and workers from abroad.

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The opinions expressed in this column reflect the views of the ownership and the editorial board.