With the war in Iraq politically on the back burner, illegal immigration is heating up as a campaign issue. The public wants action, and the candidates are scrambling to react.

Sen. Hillary Clinton's sure nomination was first questioned when she flubbed an easy debate question about driver's licenses for illegal aliens.

Sen. John McCain's recovery took off when he backed away from his support of immigration reform that did not first ensure the closure of the border.

Former Mayor Rudy Giuliani is no longer for sanctuary cities that shield illegal aliens from arrest. Like former Gov. Mike Huckabee, he's now a born-again opponent of illegal immigration.

Former Gov. Mitt Romney assures us that some illegal aliens can be deported within 90 days after he's elected.

Sen. Barack Obama may talk of change, but his relative fuzziness about illegal immigration can't last forever; at some point he will have to offer more specific proposals.

Some time ago, supporters of open borders lost the debate. The majority of Americans want them closed. They ignore the tired slurs like "racist," "protectionist" and "nativist." May Day parades with Mexican flags and heated rhetoric from the National Council of La Raza ("The Race") only turn people off.

It doesn't do any good, either, for a Mexico functionary to cry about how mean we are to want a secure border. Most Americans tuned that out long ago.

They know that Mexico cares mostly about sending north those it won't or can't feed and house — so it can skim off from them billions in remittances once they arrive in the U.S.

Mexico City, of course, could reform the country's laws and economy whenever it wants. But it changes only enough to draw in tourists or Americans looking to buy vacation homes, not to better the lives of millions of its mestizo poor in the heartland.

The spin masters may think illegal immigration is an issue that pits conservative Republicans against liberal Democrats. But it doesn't always.

Worry about illegal immigration is just as likely to mean that African-Americans are terrified of racist alien gangs in Los Angeles. Asian-Americans are frustrated their relatives with college degrees wait years to emigrate legally, while thousands without high school diplomas to the south simply break the law to enter the United States.

To the extent Democratic candidates ignore illegal immigration, or demonize those who worry over hundreds of thousands of new illegal aliens each year, or talk of guest workers and amnesty before they mention closing the borders, it is a losing issue that could alienate millions of voters.

Democratic candidates can't really claim that redneck racists are rushing to the border to clash with poor campesinos just crossing to better their lives, because many poor Democrats also resent how illegal labor drives down their own wages.

But the Republican candidates have to watch it, too. If blanket amnesty is a losing issue, so also is mass deportation — the practicality and morality of which are rarely considered by those rightly calling for an end to illegal immigration. Busing every illegal alien back to Mexico right now might resemble the past messy partition of India and Pakistan, and reopen the issue in a way that Democrats can legitimately exploit.

What then might an astute candidate advocate?

Close the border now through fencing, more agents, employer sanctions, enforcement of the law and verifiable identification. Restore faith in the melting pot by insisting that new legal arrivals learn English and the customs of the United States.

Explain to the Mexican and Central American governments that using the United States to avoid addressing internal problems — while making easy dollars off the backs of their own expatriate laborers — is over.

Finally, deport aliens who have broken the law, are not working or have just arrived. Some illegal aliens will not like the new atmosphere of tough enforcement and will go home. Others may have criminal records or no history of employment and should also leave.

But many millions of law-abiding, employed illegal aliens of long residence will wish to stay. We should allow these to remain in the United States while they apply for citizenship — if they are willing to learn promptly our language and customs.

Republican candidates must risk angering their base by ruling out mass deportation. Democrats should support closing the border tightly and quickly — and not cave in to open-borders pressure groups.

Making these tough choices is what most voters want. Candidates will either adjust accordingly or lose.

Victor Davis Hanson is a classicist and historian at the Hoover Institution at Stanford University. Reach him at author@victorhanson.com.