Arizona recently made waves with its notorious immigration crackdown. Then, on June 21, the town of Fremont, Neb., passed a law requiring would-be renters to be licensed by the city -- which could deny those licenses based on immigration status.

The Nebraska city wasn't the first to try local enforcement of national immigration laws, however. Last year, the Dallas suburb of Farmers Branch passed a similar law, banning apartment rentals to illegal immigrants. This May, the law was thrown out by a federal judge who ruled that only the federal government has the power to enforce immigration law.

There is a logic to such rulings. The notion of local immigration enforcement brings to mind a conversation I had 20-odd years ago with a friend in another little mountain town. We were bemoaning the arrival of People of Money (the politically correct term for "rich immigrants who screw up your community") and he observed that in his mostly Hispanic town, local lore had it that long ago, "If you wanted to move here and set up something, you had to talk to the alcalde and get permission."

If you wanted to open a bakery, for instance, the alcalde might tell you that what the town really needed was a blacksmith or a milliner, but he'd heard that a neighboring village could use a source of fresh bread and tortillas. And if you planned on buying four lots and scrapping their casas so you could build a mansion facing the plaza, the alcalde could tell you to move on with your destructive schemes.

We laughed about it. Such local powers could indeed solve some of our local problems, but would doubtless cause many more, such as the protection of price-gouging monopolies and the empowerment of ugly forms of discrimination.

So it's just as well that our mayors don't enjoy that kind of authority. Still, it does raise the question: Why don't American towns, cities and counties have the legal power to control immigration, to say who can visit or live there, and who can't?

For starters, our towns, cities and counties are chartered and defined by state governments. That's where they get their legal powers, and a state government cannot grant or delegate authority that it does not itself possess.

So we need to look at the powers of state governments, which are largely determined by the U.S. Constitution. There the federal government reserves certain governmental powers to itself while leaving the states free to exercise others.

Two provisions are relevant. Article I, Section 8 provides that the U.S. Congress "shall have Power ... To establish an uniform Rule of Naturalization." That means that only the federal government grants citizenship to immigrants. Wyoming and New Mexico can't have their own laws for becoming a citizen.

The other provision is in Article I, Section 9: "The Migration or Importation of such Persons as any of the States now existing shall think proper to admit, shall not be prohibited by the Congress prior to the Year one thousand eight hundred and eight ..."

The wording is complex because our Founding Fathers wanted to allow states like Virginia and South Carolina to import slaves for 20 years, at which time Congress could outlaw the trans-Atlantic slave trade -- which it did on Jan. 1, 1808.

However, it also means that after that date, only the U.S. Congress -- not the individual state governments -- had authority over immigration from other countries.

Federal policy toward resident immigrants was a contentious matter, almost from the start. John Adams was the second president, from 1797 to 1801. For reasons too complex to detail here, war with France (then undergoing its own revolution) was a real possibility.

Adams and the majority Federalist Party in Congress worried about the loyalty of French emigrés in the United States. They passed three Alien Acts in 1798.

One, repealed in 1802, raised the residency period for naturalized citizens to 14 years. Another, still in effect, empowered the president to arrest and deport resident aliens if their home countries were at war with the United States. The third, which expired in 1800, allowed the president to deport any resident alien deemed "dangerous to the peace and safety of the United States."

Back then, the runner-up in the Electoral College became vice president. That was Thomas Jefferson, who was Adams' leading political antagonist. Jefferson arranged for the Kentucky Legislature to pass a resolution that he had secretly written.

You could call Jefferson the original "tenther." The 10th Amendment provides that "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."

Since there was no specific constitutional authority giving the federal government power over resident aliens, Jefferson argued, then under the 10th Amendment, it was a state matter. Thus the law "which assumes power over alien friends, not delegated by the Constitution, is not law, but is altogether void, and of no force." In other words, Kentucky resolved to nullify the federal law.

Since one Alien Act soon expired and another was quickly repealed, the issue was never tested. And even though Jefferson, who became president in 1801, feared that the federal government lacked the constitutional authority to make the 1803 Louisiana Purchase, he went ahead with it anyway. So even if he started out a Tenther, he didn't stay that way.

Thus it became settled that states don't control foreign immigration or naturalization. But what about internal migration from state to state?

That became an issue during the Great Depression. In 1936, Colorado Gov. Edwin C.  Johnson declared martial law along the state's southern border with Oklahoma and New Mexico. National Guardsmen set up check stations to turn back "paupers and aliens."

Johnson was roundly criticized by Colorado newspapers and other states threatened to boycott Colorado products. After just 11 days, he called back the Guard and stopped trying to control his state's borders.

California was a different story. In 1933, California passed a law making it a misdemeanor to bring in, or assist in bringing in, "any indigent person who is not a resident of the State, knowing him to be an indigent person."

A lay preacher named Fred Edwards brought his wife's brother, Frank Duncan, to live with them in Marysville, Calif. The brother-in-law was known to Edwards as "an indigent person." After Duncan applied for relief in California, Edwards was convicted of importing a pauper and sentenced to six months in jail. He appealed. The state court upheld the conviction, but the U.S. Supreme Court overturned it in 1941.

While the court recognized that "the huge influx of migrants into California in recent years has resulted in problems of health, morals, and especially finance," it observed that a state cannot wall itself off from the problems of the nation as a whole.

Mainly, though, the U.S. Constitution grants Congress the power "To regulate Commerce ... among the several States," and the court held that this effort to regulate the movement of people from state to state was "an unconstitutional barrier to interstate commerce."

Add all this up, and you can see how immigration is strictly a federal responsibility. States (and thus their political subdivisions like towns and counties) have no authority to determine who is allowed to enter their borders. They cannot determine who can become a citizen, and they cannot control who is allowed to enter the United States. So even though it might be fun to imagine local laws to protect us from immigrants like rich Texans, gaudy Californians and condescending New Yorkers, let alone folks from other countries -- it's not within local power. Under our Constitution, it's a federal matter.