President Obama's latest political ploy — granting new “rights” out of thin air, by executive order, to illegal immigrants who claim that they were brought into the country when they were children — is all too typical of his short-run approach to the country's long-run problems.

Whatever the merits or demerits of the Obama immigration policy, his executive order is good only as long as he remains President, which may be only a matter of months after this year's election.

People cannot plan their lives on the basis of laws that can suddenly appear, and then suddenly disappear, in less than a year. To come forward today and claim the protection of the Obama executive order is to declare publicly and officially that your parents entered the country illegally. How that may be viewed by some later administration is anybody's guess.

Employers likewise cannot rely on policies that may be here today and gone tomorrow, whether these are temporary tax rates designed to look good at election time or temporary immigration policies that can backfire later if employers get accused of hiring illegal immigrants.

Why hire someone, and invest time and money in training them, if you may be forced to fire them before a year has passed?

Kicking the can down the road is one of the favorite exercises in Washington. But neither in the economy nor in their personal lives can people make plans and commitments on the basis of government policies that suddenly appear and suddenly disappear.

Like so many other Obama ploys, his immigration ploy is not meant to help the country, but to help Obama. This is all about getting the Hispanic vote this November.

The principle involved — keeping children from being hurt by actions over which they had no control — is one already advanced by Sen. Marco Rubio, who may well end up as Gov. Romney's vice-presidential running mate. The Obama executive order, which suddenly popped up like a rabbit out of a magician's hat, steals some of Sen. Rubio's thunder, so it is clever politics.

But clever politics is what has gotten this country into so much trouble, not only as regards immigration but also as regards the economy and the dangerous international situation.

When the new, and perhaps short-lived, immigration policy is looked at in terms of how it can be administered, it makes even less sense. While this policy is rationalized in terms of children, those who invoke it are likely to do so as adults.

How do you check someone's claim that he was brought into the country illegally when he was a child? If Obama gets reelected, it is very unlikely that illegal immigrants will really have to prove anything. The administration can simply choose not to enforce that provision, as so many other immigration laws are unenforced in the Obama administration.

If Obama does not get reelected, then it may not matter anyway, when his executive order can be gone after he is gone.

Ultimately, it does not matter what immigration policy this country has, if it cannot control its own borders. Whoever wants to come, and who has the chutzpah, will come. And the fact that they come across the Mexican border does not mean that they are all Mexicans. The can just as easily be terrorists from the Middle East.

Only after the border is controlled can any immigration policy matter be seriously considered, and options weighed through the normal Constitutional process of Congressional hearings, debate and legislation, rather than by Presidential short-cuts.

Not only is border control fundamental, what is also fundamental is the principle that immigration policy does not exist to accommodate foreigners but to protect Americans — and the American culture that has made this the world's richest, freest and most powerful nation for more than a century.

No nation can absorb unlimited numbers of people from another culture without jeopardizing its own culture. In the 19th and early 20th century, America could absorb millions of immigrants who came here to become Americans. But the situation is entirely different today, when group separatism, resentment and polarization are being promoted by both the education system and politicians.

Thomas Sowell is a senior fellow at the Hoover Institution at Stanford University. His website is www.tsowell.com.