When American politicians get around to reforming their immigration laws, they tend to look backwards. They seek to address immigration problems in the past rather than look ahead and set policy that will strengthen the nation in the future.

That’s true, in my opinion, of the bipartisan majority that supported the immigration bill passed by the Senate last spring and of its most vocal critics. And it’s certainly been true of immigration legislation in the past.

Start with the 1924 law, the first federal legislation to bar immigrants for reasons other than disease or inability to support themselves.

The 1924 Act came 32 years after the opening of the Ellis Island immigration station in New York Harbor in 1892. That was a time that saw a sharp decline in immigration from northwestern Europe (Ireland, Germany, Scandinavia) and a huge increase in immigration from eastern and southern Europe.

Many Americans worried that the Poles and Jews, Serbs and Slovaks, southern Italians and Greeks of the post-Ellis Island immigration could not be assimilated into American culture.

In fact, institutions from public schools to Henry Ford’s citizenship classes were doing a good job of Americanization (Theodore Roosevelt’s word). But the 1920s Congress was worried that the urban Ellis Islander masses would change the national character.

So they imposed quotas on immigration from countries in proportion to their share of American ethnic stock in the 1890 Census — before Ellis Island immigration began.

This turned out to make less difference than it might have, since immigration slowed below quota levels in the Depression-era 1930s and wartime 1940s. As a result, the nation missed out on contributions that might have been made by highly skilled people fleeing Nazism and Communism.

The 1965 Immigration Act was passed to repeal the 1924 quotas and undo what advocates considered an injustice and a mistake. When asked whether there would be a flood of immigrants from Latin America and Asia, experts said no — immigrants come from Europe.

We know how that worked out. The family reunification provisions carried over from the 1924 Act (to propitiate Ellis Islanders who had become voters) opened the way for millions of Mexicans and other Latin Americans, while the porousness of the southern border let in millions of illegals.

Congress tried to deal with this in the 1986 Act, which legalized illegals (about half took up the offer). But opposition to tamperproof identity cards from both Left and Right meant that sanctions against employers hiring illegals were toothless, and illegals kept coming.

The 2013 Senate bill, like the failed 2006 and 2007 bills, provides for legalizing illegals, and there’s a consensus now that those brought in illegally as children who meet certain conditions (“dreamers”) should be legalized.

But it’s not clear that the bill’s provisions for employer verification will be enough to deter future illegals.

The bill’s opponents concentrate their fire by demanding tougher border security. But since 2007, net migration from Mexico to the United States has been zero.

Mexican and other Latin immigrants got burned when housing prices collapsed in 2007-08. They’d been given mortgages on lenient terms, thanks to imprudent government policies.

Their dream of accumulating wealth through ever-rising housing prices has been shattered. We’re unlikely to see mass Mexican and Latin migration of the magnitude of 1982-2007 again. The fixation on border security is backward-looking.

A forward-looking immigration policy would focus on encouraging high-skill immigration, as Canada and Australia have done, by reserving slots for those scoring well on their point systems.

With a “new normal” economy that includes many long-term unemployed and sluggish economic growth, we don’t need lots more low-skill people admitted through extended family reunification provisions.

The Senate bill goes a little ways in the right direction by expanding H-1B visas sought by high-tech employers. But these tend to tie immigrants to employers who can pay below-market wages.

More openings for high-skill immigrants could trigger one of those surges in immigration that I described in my recent book, “Shaping Our Nation: How Surges of Migration Transformed America and Its Politics.”

A nation with sagging job creation and stagnating test scores could use a large infusion of entrepreneurs and engineers. Today’s America needs more job creators, not job seekers.

Unfortunately, there is no strong lobbying force for such a forward-looking reform. The politicians once again seem to view the issue through the rear-view mirror.

Michael Barone, senior political analyst for The Washington Examiner, is a resident fellow at the American Enterprise Institute, a Fox News Channel contributor and a co-author of The Almanac of American Politics.