WHEN QUIZZED on the problem of illegal immigration at their debate the other night, the Republican presidential hopefuls were by turns vague, evasive, confused, contradictory and — in the notable case of Rep. Ron Paul of Texas, who opposes a border fence because it might prevent law-abiding Americans from withdrawing their savings and fleeing to Mexico in a crisis — harebrained.

If a majority of the GOP aspirants agreed on anything, it was that nothing meaningful can be done about the nation’s dysfunctional immigration system and the presence of 11 million undocumented immigrants until the southern border is “secure.” And as Texas Gov. Rick Perry asserted, “It is not safe on that border.”

That sounds very grave. There’s just one problem: The border today is more secure than it has been in years, according to virtually every yardstick accepted by Republican and Democratic administrations for decades. Illegal crossings, as measured by Border Patrol apprehensions, are at their lowest level in 40 years, and rates of nearly all measurable crimes are plummeting in border communities.

In truth, then, the real message on immigration from most of the candidates is this: We can’t fix the broken system, or deal with illegal immigrants until, well, ever. Because even if we understand that 11 million people cannot be deported and must be granted some form of amnesty — the dreaded word! — our conservative base will punish us if we admit it, let alone undertake it.

Mr. Perry struck first, accusing President Obama of possessing terrible intelligence, or being an “abject liar,” for telling a crowd in El Paso that the border is safer than it’s ever been. In fact, it’s Mr. Perry whose relationship to the truth is at arm’s length. In his El Paso speech, Mr. Obama merely claimed “important progress” on securing the border, which is statistically undeniable, and he cited the huge additional resources the federal government — starting with President George W. Bush — has dispatched there in recent years.

Beyond that, Mr. Perry had nothing significant to contribute to the conversation on immigration. That may be because his positions are in fact much more closely aligned with Democratic views, and reality, than his own party’s hard-line stance.

Mr. Perry has opposed fencing the entire 2,000-mile border, correctly labeling it a “preposterous idea” that wouldn’t deter many illegal crossers. He favors a sensible guest worker program to meet the labor market’s demand, a proposal that many Republicans regard as amnesty by another name. And he was the nation’s first governor to sign legislation extending tuition breaks to the blameless children of illegal immigrants who attend colleges and universities. That in particular is an act of heresy for most of today’s GOP politicians.

Then there was Mitt Romney, whose position on the issue is a sterling example of incoherence. The former Massachusetts governor twice declared that “we ought to have a fence” running the length of the border, but he acknowledged that any fence would be highly porous and ineffective. That amounted to a pledge to spend billions of dollars to no meaningful effect.

Aside from opposing amnesty, the former Massachusetts governor had no ideas — or none he cared to share — about dealing with the 11 million undocumented immigrants already here. But he did stress the need to crack down on employers and tuition breaks that he said provide a “magnet” attracting illegal immigrants in the first place — an oblique shot at Mr. Perry.

In fact, the real magnet for illegal immigrants has been the U.S. economy, which has generated many low-wage jobs that the vast majority of Americans have not wanted. And the core problem has been Washington’s failure to devise a workable system to provide an adequate and legal supply of labor.

Among the other major Republican candidates, there wasn’t much more insight or logic on offer. Rep. Michele Bachmann of Minnesota ducked two straight questions on what to do about the 11 million. Former senator Rick Santorum of Pennsylvania said that he loved immigrants — his father and grandfather, to name two — but that any discussion of the 11 million undocumented ones should come later.

Former Utah governor Jon Huntsman Jr. advocated unspecified “punishment” for the undocumented, while helpfully offering a reminder that they are “human beings” and avoiding any explicit mention of his long-standing support for some form of amnesty.

And then there was Ron “Don’t Fence Us In” Paul.

As usual, no one in the Republican pack bothered to define what they mean by “securing” the border, the reason being that those goal posts will never stop moving.

Mr. Romney and Mr. Perry want more manpower and technology on the border. But they never mention that Border Patrol deployments have already tripled over the past 15 years, not counting 1,000 more officers being recruited and trained in the current year, let alone the addition in recent years of thousands more boots on the ground from an alphabet soup of other federal agencies plus the National Guard.

Ms. Bachmann wants “a fence on every part of that border,” by which we assume she means the 1,350 miles not already fenced. But fences are costly and easily defeated (think ladders and tunnels). More to the point, they are utterly irrelevant to the 40 percent or more of undocumented immigrants who enter the United States legally, then overstay their visas.

If there was one candidate who dared say something sensible, it was former House speaker Newt Gingrich. Maybe being stuck near the bottom of the pack in the polls gave him courage to mention the unmentionable: There must be “a much more humane way” of dealing with illegal immigrants, Mr. Gingrich said, than imagining America can “deport millions of people.” Amen.