Estimate of Immigration Overhaul’s Cost Gets Mixed Reviews on Right

A researcher whose fiscal calculations have provided crucial support in the past for conservative opponents of an immigration overhaul released a report on Monday, predicting that a proposal now in the Senate would vastly increase the government deficit in coming decades. But this year the estimates, by Robert Rector of the Heritage Foundation, have received decidedly mixed reviews from conservatives.

Mr. Rector and his co-author, Jason Richwine, estimated that offering a pathway to citizenship for 11 million illegal immigrants, which is part of a plan by a bipartisan group of senators to overhaul the immigration system, would generate a “lifetime fiscal deficit” for the government of $6.3 trillion.

An earlier, similarly high calculation by Mr. Rector of the cost of giving legal status to illegal immigrants was a powerful organizing tool in 2007 for opponents of a comprehensive immigration reform bill proposed by then-President George W. Bush. Citing Mr. Rector’s warnings of a huge drain on taxpayer resources, conservative activists rose up to defeat that legislation.

This year, Mr. Rector had somewhat different findings, and they received a very different reception from leading conservatives.

The new study assumes that large numbers of immigrants formerly in the country illegally would eventually use government programs for low-income Americans, after a 13-year period in which they would not be eligible for those benefits under the terms of the bill.

The steepest costs Mr. Rector projects would come toward the end of the immigrants’ lives, after they had become United States citizens and retired. At that point, he estimates, the difference between what they would pay in taxes and what they would use in government services would leave a fiscal deficit of $22,700 a year for each immigrant.

“You simply do not want to give illegal immigrants access to the welfare state,” Mr. Rector said during a conference call with reporters. Doing so, he said, would be “ruinously expensive.”

Hours after Mr. Rector presented his findings at a news conference at the Heritage Foundation in Washington, Haley Barbour, a Republican leader and former governor of Mississippi, convened his own press call to dismiss the study.

“This a political document,” Mr. Barbour said. “This gigantic cost figure that the Heritage Foundation puts out is actually the cost over 50 years. If you put the 50-year cost of anything in front of the public, it is going to be a huge number.”

Mr. Barbour, who is among a growing number of Republican leaders who have urged the party to take a less hard-line approach to immigration, criticized Mr. Rector for failing to estimate the economic benefits of bringing immigrants into the legal system, and for underestimating the potential for economic improvement over time among immigrant families.

Grover Norquist, the conservative anti-tax crusader, has also spoken out in recent days to pre-emptively dispute Mr. Rector’s claims. An analysis posted Monday on the Web site of his organization, Americans for Tax Reform, called the cost estimate “wildly overblown,” arguing that the study had, among other things, lumped native-born Americans into many of its calculations.

Surprisingly, some of Mr. Rector’s findings echoed what the senators sponsoring the immigration bill have said about its fiscal impact over the 13 years before formerly illegal immigrants would be allowed to become American citizens. He estimated that “tax payments would increase more than government benefits” during that period, reducing the deficit.