When Sen. Rand Paul launched his presidential campaign in April, he did so after a year of hype about his campaign's organizational strength, his challenge to the GOP's foreign policy orthodoxy, and his hopes of winning over African-American voters.

He's hardly ever been heard from since. Once viewed as the ultimate outsider, Paul has been completely overshadowed by Donald Trump, Ben Carson, and Carly Fiorina, and he's plummeted to the low single digits in the polls. Even in New Hampshire, an early state where he's long polled among the top three contenders, Paul has fallen to eighth place.

Now, in perhaps the most embarrassing development for Paul yet, one of the three major Super PACs backing him — Purple PAC, which had raised $1.3 million for him by the end of June — has publicly announced that it won't work on his behalf. (The two other Super PACs remain operational, though the head of one was indicted last month.)

In a remarkable on-the-record interview with Politico's Alex Isenstadt, Purple PAC's Ed Crane — the former head of the Cato Institute, a libertarian think tank — declared that Paul's campaign had been so poorly run that he no longer had any intention of fundraising for "a futile crusade." Crane added, "I want to grab Rand by the lapels and say, 'What are you doing?'" (Crane later told Reason.com that he actually came to this conclusion "months" ago and that he could still change his mind if Paul shifts his approach, but this is the first public indication of it.)

Crane's critique is simple: Paul moved too far toward mainstream Republicanism, and his libertarian views "disappeared." Rand tried to be all things to all people, and in so doing lost what made him — and his father, Ron Paul — unique. "He has to be the peace and free enterprise candidate," Crane told Reason's Brian Doherty.

Rand downplayed his libertarianism because he wanted to win

When a campaign begins to flail, disappointed "friends" frequently come out of the woodwork to sermonize about what the candidate should have done differently. As Matt Yglesias has pointed out, though, these Monday morning quarterbacks' ideas are often even worse.

Such seems to be the case here. It's no surprise that Ed Crane — a longtime libertarian true believer who co-founded the Cato Institute back in the 1970s — wanted Paul to run an ideologically purer campaign. But doing so would have sidelined Paul's campaign like his father's — limiting his appeal to a small part of the Republican electorate.

Instead, Rand actually wanted to win the nomination. So he decided to try to appeal to a broader audience. For instance, he retained his anti-interventionist foreign policy views in general, but came out against an Iran deal that Republican voters overwhelmingly distrusted.

Similarly, Paul has remained quite conservative on economics, but has sanded down the rougher edges of his father's platform. "There’s no talk from the Kentuckian about ending the Federal Reserve, no quoting Friedrich Hayek and no laments about how the U.S. deserves a share of blame for terrorism," James Hohmann wrote in April. Paul himself told Hohmann his approach was "libertarian-ish, which means I have some libertarian impulses."

So far, this approach hasn't worked, and many are speculating that the end of Paul's campaign may be near (though his team denies it). But it was a reasonable strategy. Indeed, it's Donald Trump's anti-immigration and anti–trade deal rhetoric that's been hot among the GOP base this year. So while it might be comforting for libertarian activists to blame Paul's heresies for his failure to catch on, there's no reason to assume Ed Crane's approach would have worked better.