For the past few years, an anti-immigration hysteria has been a key issue in American politics, but is it possible that, despite the hysteria, immigrant entrepreneurs are the very people fueling the U.S. economy?

The Ewing Marion Kauffman Foundation's Index of Entrepreneurial Activity shows that in 2005, approximately 350 out of every 100,000 immigrants in the United States started their own businesses each month. Only 280 out of every 100,000 native-born Americans were doing the same. The Foundation has also released a 2007 study showing that, from 1995 to 2005, 25.3 percent of the new technology and engineering companies in the United States had at least one immigrant founder.

"Immigrant entrepreneurs are taking risks, and that's exactly what the country needs," says Jonathan Bowles, director of New York's Center for an Urban Future. "They've become a significant engine of growth for America."

The 2007 Kauffman study also shows that a majority of immigrant engineering and technology entrepreneurs came to the United States for school or a job opportunity. Serhat Pala, founder of Test Country—No.1,548 on this year's Inc. 5000 list, immigrated to the Unites States from Turkey to pursue a graduate degree in business. He said he found his new home to be a "welcoming, entrepreneurial, pro-business environment."

This does not mean, however, that starting a business, or even getting into the country for that matter, is a simple task. According to the National Venture Capital Association's recent survey of immigrant business owners in the Unites States, two-thirds of survey respondents agreed with the statement: "It has become more difficult to enter the United States and start a company than when I started my company."

Though citizenship is not a requirement for starting a business, those who do make it into the United States often find language barriers, start-up costs and regulation compliance can stand in the way of immediate success.

After losing his first job here, Indian-born Aejaz Sareshwala, founder of Ace Iron—No. 1,471 on the Inc. 5000, struggled with his family to merely survive. "With no money and a bleak future looming ahead," he said, "We thought we may have to return to India, where at least we could live comfortably and with respect."

But for those who surmount the odds, building a thriving business is more than just a personal success. "We ought to look at immigrant entrepreneurs as a really positive solution to a lot of America's problems," says Bowles. "They make a significant positive impact, and I think it's only going to get bigger in the future."