Although some businesses may be small, their role in the U.S. economy is huge. Small businesses — those employing fewer than 500 people — account for 99.7 percent of employer firms and give jobs to about half of the people working in the private sector. And they have been a traditionally reliable job-creating engine for the economy, responsible for an amazing 64 percent of net new jobs, according to the Bureau of Labor Statistics. But can that continue? Some strong headwinds are confronting…