Respect for precedent is being urged as a reason to stick with Roe v. Wade and condemn “culture warriors” such as Antonin Scalia for wanting to discard it. But it is not, of course, a reason to stick with Bowers v. Hardwick and condemn Anthony Kennedy for discarding it the Lawrence decision. Conservatives have made this point before, but it’s worth repeating.

I wonder, though, whether we’re missing a deeper point. Roe is supposed to be sacrosanct in part because many people have “relied” on it. I think this is overstated. It can scarcely be denied that many people have relied on the possibility of getting a legal abortion in the event of contraceptive failure. But have many people really relied on the inability of state legislatures to make incremental restrictions? Many, many people aren’t aware that third-trimester abortions are legal, and therefore cannot be said to be relying on their Supreme Court-protected status.

But let’s ignore that point and assume that many people have relied on Roe. Isn’t this kind of “reliance” test for precedent a one-way ratchet in favor of activist precedents? People may rely on an invented constitutional right, but they don’t rely on the absence of one. The only people who “relied,” pre-Lawrence, on the government’s ability to pass laws against types of sexual conduct were legislators and, I suppose, everyone acting in his capacity as a voter. That’s not the type of interest that people have in mind when they talk about “reliance.”

It may be that recognizing the force of precedent always has this asymettric effect: A precedent that is grounded in the Constitution doesn’t need to lean much on its precedential force. In practice, however, making a big deal out of “reliance” might make justices more willing to overturn “passivist” precedents and thus facilitates departures from the Constitution. I’m willing, however, to be instructed by my betters here.