Michael Brendan Dougherty tries  to persuade libertarians not to give up on Rand Paul:
Instead of saying “I’m done” and walking away forever, libertarians should take as much good policy as they can get. They should welcome limits on bad policies, even if these limits are incremental. And when they disagree, say so. Then grant yourself the liberty to support Rand Paul again later.
The trouble with this is that Dougherty is treating the drop in libertarian (and some conservative) support for Paul as if it is their responsibility to fix things by being more willing to take what little they can get. Normally, when a politician repeatedly does things that his most likely supporters oppose it is the politician that is expected to repair the breach that he has opened up. If he doesn’t, he can reasonably expect those supporters to withhold their backing. There would probably be more patience with attempts at coalition and bridge-building if Paul’s odder recent positions appeared to be something more than just caving to the hawks on one issue after another. It would also help if these positions made any sense on their own terms, but they  frequently  haven’t . The decision to sign the Iran letter has been the last straw for many of his past supporters for obvious reasons. One of these was that the letter was just the latest in a string of bad and sometimes inexplicable moves that Paul has made in a mostly vain effort to shield himself from hard-line attacks. He has generally gone into something of a “defensive crouch” on foreign policy, which more or less negates much of what drew antiwar libertarians and conservatives to him in the first place. There have always been pluses and minuses to Paul’s foreign policy , but in the last year the minuses have been piling up and they aren’t being offset.
So far, Paul has been held to a pretty low standard by antiwar libertarians and conservatives in the name of pragmatism. At this point, they (we) are expected to keep lowering the bar so that Paul may continue to clear it. Take his support for the war on ISIS, for example. It is better that he wants to restrict the scope and duration of the war on ISIS than if he did not, but he shouldn’t be supporting such an unnecessary war at all. That’s not an unreasonable thing for people on the antiwar right to expect from someone whose main claim on their support is his past opposition to unnecessary foreign wars. It is becoming increasingly difficult to distinguish him from the rest of his party on the issues that were supposed to set him apart, and so he is bound to receive less support as long as that is the case. Paul could try to fix this, but it may be too late to undo the damage. For the sake of trying to find common ground with people in the GOP that loathe him, he has burned bridges with many of the people that were once most likely to be on his side.