Chris Pope issues National Review Online readers a warning about the political debate surrounding health insurance for people with pre-existing medical conditions.

On December 14, a Texas district-court judge revived political fights over the Affordable Care Act by ruling the legislation unconstitutional. Senate Minority Leader Chuck Schumer (D., N.Y) pounced, arguing that “it puts a lot of our Republicans in a box” because “they said they want to preserve preexisting conditions.” He was echoing the peculiar cheer of Nancy Pelosi, soon to be speaker of the House once again, last month: “Let’s hear it for preexisting conditions!”

But “preexisting condition” simply refers to someone trying to purchase insurance after they have become sick — not necessarily someone with a major illness that would have made them unable to find affordable coverage on the pre-ACA individual market.

Republicans should be careful not to conflate these two groups. They should support subsidies (as currently provided through the ACA exchange) for uninsurable individuals. But they should resist efforts by Democrats to suggest that those with “preexisting conditions” are necessarily uninsurable in an attempt to force all Americans into overpriced, highly regulated, and publicly subsidized ACA plans — especially now that more fairly priced alternatives are widely available.

A disqualifying preexisting condition is not merely an objective medical status, but also a behavioral response to insurance-market rules. The number of people disqualified by preexisting conditions depends on the incentives such rules provide individuals to sign up for coverage before they get sick.

Estimates of the number of people with preexisting conditions therefore vary immensely, including in different reports from the same organizations.