CLARKONOMICS: In the aftermath of the Supreme Court's immigration ruling, you'll hear a lot of pundits talking about what the decision means for the Democrats and the Republicans. But I want to look at it in a different way that strips the politics out of illegal immigration.

Today, there are 40 million people in the U.S. who were foreign born. That's almost 15% of our population. Most are legal in this country. But it has been a big influence on the debate in the United States for a few reasons.

According to what I read in The Financial Times of London, you'd have to go back 100 years to find a time when we had as high of a foreign-born percent of the U.S. population as we now have. We had a massive wave of immigration in the late 1800s and early 1900s. Then we also had a huge national backlash against both legal and illegal immigrants.

After that whole period ended back in 1910s, every decade after that, the number of residents that were foreign born dropped and dropped. And it didn't start climbing again until the 1990s.

I believe it is a natural reaction in people, in a nation of immigrants, where we go from being welcoming to being hostile. I don't know exactly where that tipping point is, but it's only human nature.

But there's something that makes it more intense this time around. And that something is that American -born men are earning no more today -- in inflation-adjusted dollars -- than they were in 1970.

When you look at polling, there's been a big gap in how U.S.-born men feel vs. how U.S.-born women feel. That's why we have all these men saying, "These foreigners are taking our jobs," and you see states like Alabama and Georgia that have suffered mightily on the employment front passing stringent laws about illegal immigration.

So we are in an era where there are natural reasons why there's so much anger on this topic. I expect other states to restrict illegal immigration within the boundaries of what the Supreme Court ruled is legal.

Meanwhile, the third factor influencing the debate is this: One third of the U.S. economy is now integrated with the rest of world. That's a big factor for men without college educations in the job market -- and it's not going away.

The solution? We need to have paths to continual training and continuous education as adults, not just as kids.