J. Scott Applewhite, ASSOCIATED PRESS
Sen. John Cornyn, R-Texas, center, flanked by Sen. Michael S. Lee, R-Utah, left, and Sen. Lindsey Graham, R-SC., right, discuss an amendment as the Senate Judiciary Committee meets in a markup session to examine proposed changes to immigration reform legislation, on Capitol Hill in Washington, Thursday, May 9, 2013. A bill to enact dramatic changes to the nation's immigration system and put some 11 million immigrants here illegally on a path to citizenship is facing its first congressional test as lawmakers contest specifics in the 844-page legislation.

During Reagan's presidency, Sen. Pat Moynihan, D-N.Y., upset liberals by saying, "The Republican Party has become the party of ideas." One of the reasons that was true was Heritage Foundation.

Created in 1973 in response to what its founders considered to be the ideological heresies of the Nixon Administration, over the years Heritage built its reputation by working in concert with other conservative voices and producing scholarship good enough that even those who disagreed with it admitted that it always did its homework well.

No more. Last week its reputation was severely damaged by the release of a very lengthy study on the issue of immigration. Its conclusion? "Amnesty" — Heritage's definition of the immigration deal being worked out in the Senate in a bipartisan way — will cost the American Taxpayer $6.3 trillion dollars. Wow.

The real "wow" is the shoddy, perhaps even dishonest, way by which the report arrives at that figure.

Heritage concedes what every other study has shown, which is that our current population of illegal immigrants pays more in taxes than they consume in taxpayer funded services and that will likely be true for at least 10 years. The report says that net plus will turn into a $6.3 trillion net minus if you look at the next 50 years instead.

Here's its logic: 1) The majority of current illegal immigrants are low skilled, poorly educated people who add little or nothing to the economy. 2) All of their children and grandchildren — again, we are talking 50 years – will be the same. 3) If we refuse to pass a bill that gives them and their children a pathway to citizenship, they will have no reason to stay in America. Most will start to leave around the time they turn 55. 4) According to our calulations, the few that stay will cost the taxpayer $1 trillion over 50 years, but if all of them stay, the price tag will jump to $6.3 trillion.

All of these propositions are, of course, unknowable. Who can predict with any certainty what will happen during the next 50 years? My grandfather was born into a lower-class family in England and came to America without a visa. He had only a fourth-grade education; Heritage's stereotypical unskilled immigrant. Fifty years later, he was one of Utah's most prominent businessmen and had given all five of his children a college education, even the girls, at a time when that was rare.

Another question: Even Heritage does not propose lining up 12 million undocumented immigrants and marching them across the border at the point of a bayonet. They are going to stay whether a bill is passed or not. How does requiring them to pay a fine in order to change their status hurt the taxpayer?

The response to the Heritage report has been swift and devastating, all across the political spectrum. The Cato Institute, where Ayn Rand is an icon, denounced it strongly. So did Americans for Tax Reform and Rep. Paul Ryan, Republican House budget chairman and Mitt Romney's running mate. Haley Barbour, one of the most effective chairmen of the Republican National Committee in history, dismissed it as irrelevant — just "a political document." The Wall Street Journal, which has worked closely with Heritage in the past, editorialized against it. The Congressional Budget Office documented its more obvious methodological faults.

Once a strong and respected force in the conservative movement, the Heritage Foundation is now being dismissed as nothing more than a political front for the tea party movement.

It's sad to see an old friend go astray.

Robert Bennett, former U.S. Senator from Utah, is a part-time teacher, researcher and lecturer at the University of Utah's Hinckley Institute of Politics.