President Obama and Mitt Romney have made much of their differences on illegal immigration. But their positions on legal immigration are much the same, particularly when it comes to high-skill immigrants. Both want to grant permanent residency to foreign students who receive degrees in math, science and engineering, and both want to lift country-based caps and other quotas on visas for high-skilled immigrants.

In part, this seeming bipartisan consensus is a product of mounting evidence for the economic benefits of high-skills immigration. According to a new report from the Partnership for a New American Economy, 76 percent of the patents awarded at America's most innovative universities "had at least one foreign-born inventor." But only 7 percent of green cards are awarded for employment-based reasons.

Green cards (Partnership for a New American Economy)