John McCain promises that if elected president, he’ll appoint strict-constructionist judges in the mold of Roberts and Alito. Some of his conservative critics say he actually might end up appointing moderates, but they don’t seem to recall that Ronald Reagan, the greatest of conservative presidents, himself appointed two famously moderate justices: Sandra Day O’Connor and Anthony Kennedy.

As the Wall Street Journal points out, skeptics who distrust McCain need to recognize the difference between the chance that he could disappoint us by appointing moderates, and the certainty under Obama or Clinton that they will outrage us by appointing activist liberals. If Democrats add two or more such justices to the Supreme Court, it will end all chance of reversing Roe v. Wade, or making continued progress on the social and cultural issues that many conservatives care about most.

On judges, and a half dozen other crucial issues, this election will offer voters a potent and important choice.