Sen. Rand Paul (R-Ky.) (Daniel Acker/Bloomberg)

Libertarian ideas are set to have their widest airing in the American electoral arena for generations, perhaps ever. Or at least, that’s the buzz as Sen. Rand Paul (R-Ky.) launches his campaign for the GOP presidential nomination.

Since winning a U.S. Senate seat in 2010, Paul has been carving out his own brand, distinct from his sometimes-controversial, more ideologically rigid dad, former representative Ron Paul (R-Tex.). Rand’s brand is one that Reason’s Nick Gillespie has astutely described as “libertarian-ish.”

That “ish”-ness, inevitably, gives some would-be supporters qualms about his bid. Paul’s aides have tried to argue that most libertarians will come around to “Stand with Rand,” and that it’s only the weird, petulant fringe purists who aren’t already enlisting.

Ignore the straw men and caricatures Paul’s strategists are, no doubt, eager to triangulate against during the GOP primary. Actual libertarian-leaning voters have plenty of reasons not to be enthusiastic about Paul’s campaign, and they have nothing to do with hypothetical questions about how quickly he’d cut which government accounts.

Paul’s message is notably “libertarian-ish” not in its lack of radical depth, but in its lack of breadth. On two topics that elicit deafening chatter in today’s political conversation — gay marriage and immigration reform — we’ve heard very little from Rand Paul. (And unfortunately, what we have heard isn’t the right message.)

It’s a silence that can make his brand seem rather “un-libertarian-ish” to the nearly one quarter of the American electorate that leans libertarian, as identified by David Boaz, David Kirby and Emily Eakins in “The Libertarian Vote.” That’s a demographic that numbers in millions more than the miniscule amount of libertarian purists out there, many of whom refuse to vote anyway.

[Rand Paul launches 2016 bid: ‘We have come to take our country back’]

This quarter of American voters are “libertarian-ish,” too, just like Gillespie says Paul is. They haven’t delved into the philosophical tomes or economic treatises and they don’t adhere to an all-encompassing “libertarianism.”

But their instincts are libertarian: They’re turned off by agendas peddled by both the socially conservative right and the economically populist left. They don’t see why the government can’t keep its tentacles out of both their pocketbooks and their pants. When it comes to people who want to come to this country to work and become Americans, like most of the electorate, these voters favor reform leading to naturalization.

There is recent data that points to electoral potential in running on a broadly libertarian platform.

In 2013, I served as strategist for Robert Sarvis’s Libertarian campaign for governor of Virginia.  Sarvis took plenty of heat from Paul family fans online for supposed deviations from strict libertarian doctrine.

But the broadly libertarian campaign vision we devised — of a Virginia that’s both “Open-Minded and Open for Business,” emphasizing equally social tolerance and economic freedom — won a historic share of the vote. Sarvis ran especially strong in Richmond’s trendy, gentrifying urban precincts and in the city’s affluent and educated suburban neighbor, Henrico County.

Rand Paul speaks passionately about economic liberty, and, crucially, he’s alone among Republican contenders on issues where his “leave me alone” agenda transcends left and right like drug law reform, criminal justice reform and challenging the security state’s increasing violations of personal liberty.

But Paul appears uncomfortable extending his agenda explicitly — even modestly — to immigration reform and social issues like gay marriage at a moment when the libertarian positions on those issues have become electoral winners.

When he tries to win support in libertarian-receptive Silicon Valley, Paul has offered his free market ideas as more conducive to innovation and growth than the regulatory agenda put forth by the Democrats the tech community usually backs. But he has yet to come out in favor of immigration liberalization that this constituency is so vocal in advancing.

On gay marriage, it’s the same story. Marriage equality nationwide seems inevitable today, and libertarians were decades ahead of most of America, and even many liberals, in welcoming it.  But Paul, while saying the GOP needs voters who favor it, told Fox News the concept “offends” him.

He expounded on his distaste for same-sex marriage to CBN — aka the Christian Broadcasting Network, founded by televangelist Pat Robertson, the figure whose 1988 presidential nomination bid helped sour many libertarian-leaning voters on the GOP brand. Speaking to Robertson’s network, Paul called gay marriage a “moral crisis.”

Paul’s comments were not just the “Well, I’m not personally for it, but I don’t think the government should ban it,” line that libertarian-leaning conservatives have peddled to their cohorts for decades. Instead, he’s going for outright condemnation — which doesn’t jibe with how libertarian-leaning voters view the issue.

Striking a more conservative stance on social issues and immigration might make a certain sense: It’s part political strategy for dealing with GOP primary voters, and part natural comfort zone in the sometimes extremely conservative “constitutionalist” circles he’s traveled in with his dad for his entire life.

But ultimately, it’s the wrong choice. Paul often chides the GOP for failing to reach out to new constituencies or grow its universe of persuadable voters. So far, he seems to be yielding to the same conservative — and not libertarian-ish — positions that’s made the GOP brand less appealing to younger voters recently.