Chris Christie took on Rand Paul’s foreign-policy views last summer. Ted Cruz and Paul argued about them in the spring. Now Rick Perry and Paul are arguing about Iraq.

The other potential presidential candidates probably figure that most Republican voters are ultimately not on Paul’s side of this argument, and so engaging on it will help them. At some point, though, couldn’t the pile-on reinforce the impression that Paul is the front-runner and everyone else is competing to be the not-Paul in the race?