Larison sees potential:
[Gary Johnson] isn’t just badly positioned [to run for the GOP's presidential nomination]he’s horribly positioned, but there’s a chance that he might run anyway and have a salutary effect on the primary contest. His candidacy would force debates on civil liberties, foreign policy, and the drug war, which are all subjects where most of the other likely candidates hold misguided and sometimes appalling views. The rest of the field will all be officially pro-life*, but perfectly content with the idea of starting wars, detaining suspects indefinitely, and perhaps even torturing detainees when “necessary.” The contrast would be useful and instructive, and it might even lead some pro-life voters to insist that their leaders show more consistent respect for human life. All right, that last part is pretty unlikely, but it couldn’t hurt to try.
Larison throws in that asterisk on "pro-life" because Johnson is pro-choice but advocates overturning Roe v. Wade because he thinks abortion should be a state issue.