Haley Barbour, former governor of Mississippi, former head of the Republican National Committee, now a political fixer and influential voice in GOP circles, says he first became seriously interested in immigration policy after Hurricane Katrina.

Thousands of homes in Mississippi were destroyed, "down to the slab," Barbour said at a recent conference on immigration hosted by National Journal in Washington. Construction workers were overwhelmed; many were homeless themselves. And then, almost out of nowhere, came help.

"We were blessed with a huge influx of Spanish speakers, and I'm sure a lot of them weren't in this country legally," Barbour said. "I don't know where we would be in Mississippi if they had not come."

The "Spanish speakers" were willing to live in terrible conditions while at work building new homes. The experience led Barbour -- who favors raising the number of high-skilled immigrants admitted to the United States -- to realize that "there is also essential lesser-skilled labor that we need."

The National Journal panel reflected much of the discussion about immigration reform. Of eight speakers, Republicans and Democrats, seven favored comprehensive reform along the lines of the Senate "Gang of Eight" bill. That's what passes for balance in Washington today.

The level of agreement was so high that some pronounced the immigration policy debate to be "over." All that is left is for lawmakers to find a political agreement to enact universally accepted principles.

That view, it turned out, was too much even for a former member of the Obama administration's economic team who supports reform. "There are a lot of people who believe ... that immigrant competition has hurt them in the economy," said Jared Bernstein, once an economic adviser to Vice President Joe Biden. "We can't leave those people out of this debate because (the Congressional Budget Office) and lots of other economic analysis, including much of my own, has found otherwise. The policy debate is far from over."

Much of the discussion focused on skilled workers -- immigrants in the so-called H-1B and STEM categories, whose numbers Facebook founder Mark Zuckerberg and other tech titans would like to increase. It's a given among reformers that the U.S. needs to admit more of them, but Bernstein reminded the panelists that there remains a lot of slack in the American labor market.

"When you look at the skills shortage -- quote -- carefully, what you find is a lot of employers saying, 'I can't find the workers I need,'" Bernstein noted, "and what they're not saying is, 'at the wage I'd like to pay them.'"

It was a remarkable bit of candor in the like-minded group. But the real candor came from Barbour, who was quite open in his belief that the country needs more low-skilled workers to do awful jobs for low wages.

"If you go in a chicken processing plant in Mississippi, there's nobody in there who speaks English," Barbour said. (Poultry is his state's biggest agricultural industry.) "There is a very loud radio hanging from somewhere playing Spanish-language music. And this is hard, dirty ... work."

In fact, Barbour said, even prisoners in Mississippi's work-release program stay away from the chicken plants. "We have never had an inmate make it two days in a chicken processing plant," Barbour said. "They'd rather be in prison, literally, then work in a chicken processing plant."

"I am not very sympathetic to the idea that we're taking these jobs away from Americans," Barbour concluded.

Speaking after Barbour, Mark Krikorian of the Center for Immigration Studies -- the only participant who opposed reform -- raised a critical objection. Why don't some of the agricultural interests that Barbour mentioned, the ones that need so many low-skill workers, modernize instead? With more mechanization, they'd need far fewer workers.

"I've been to chicken plants, in Delaware, and most of the people there are Americans," Krikorian said. "It's not a horrible, filthy place to work ... much of it is actually automated."

American agriculture could adopt new technology rather than focusing solely on immigrant workers, Krikorian argued. "When you have unending sources of low-skill foreign labor, the incentive to automate is weaker."

The discussion reflected a core reality of the immigration debate. The elites of both political parties support reform. But even so, there are a few voices -- not just Krikorian, but Bernstein, too -- to remind them of the costs involved.

"Those of us who support comprehensive reform," Bernstein cautioned, "if we don't listen more carefully to those on the other side, who believe that immigrant competition hurts them, regardless of what the studies say, we're going to miss the boat and we're not going to get this right."