Doug Holtz-Eakin’s argument, as stated, makes no sense. It would be one thing to say that the immigration bill is so wildly pro-growth that a narrow focus on cost to taxpayers is misleading. We might then concede that it is possible that this cheery thought will prove a reality, while still wanting to be cautious about whether the reform really will do much to promote growth — and taking steps to make it more pro-growth. We might, for example, seek to amend the bill so that we get more high-skilled immigrants and fewer low-skilled ones, which would make the fiscal cost lower and improve its impact on growth.

But Holtz-Eakin goes extravagantly beyond this claim. He writes, “What clearly does not matter is the Left’s favorite metric for policy success: the profit or loss accruing to the government.” The notion that worrying about whether a policy will increase or lower the national debt is an exclusively left-wing preoccupation is, of course, absurd. As is the idea that it is wrong in principle to consider fiscal costs before supporting legislation.

Maybe the study really is deeply flawed, but I’d want something more persuasive than being told to plug my ears and cover my eyes as a refutation.