For Democrats, Rand Paul is going to be the gift who keeps on giving.   Forget about pinning down the newly minted Republican nominee for Kentucky’s open US Senate seat on the question of whether he thinks applying civil rights laws to businesses amounts to “too much government.” Just imagine the opportunities for asking GOP leaders—and candidates around the country—whether they happen to agree with their party’s candidate in one of the hottest Senate races of the year.

Of course, Paul will try to make it easier on his fellow partisans. He’s done his best to backtrack from his most controversial statements, saying he’s not in favor of repealing civil rights laws. But once you have to “unequivocally state that I will not support any efforts to repeal the Civil Rights Act of 1964,” the damage is pretty much done.

And this won’t be the last controversy of this kind.

The fact is that, when Paul has gotten into hot water, on this issue and a host of others, it has not been a mistake. He’s introducing Americans to libertarianism—not as a political slogan but as an ideology whose followers take very seriously the work of downsizing government. So seriously that they would even get rid of the good parts.

Of course, liberals and conservatives differ on how to define “the good parts.”

But the thing is that liberals and conservatives—for all their disagreements—really do think there are good parts. For instance, they pretty much agree that it is appropriate to impose basic civil rights mandates on business.

Serious libertarians don’t. For them, government is, at best, a necessary evil—with the emphasis on the “evil.” Rand Paul has repeatedly given interviews, not just in the distant past but recently, in which he has expressed discomfort with civil rights mandates—not just with regards to protections for minority groups but also for people with disabilities. The Louisville Courier-Journal editorial board refused to back him in the Kentucky primary because it said Paul “holds an unacceptable view” on civil rights.

The point here is not to suggest that Paul is a serious racist. He says he is not and that he “abhors” discrimination of any kind.

The point is that he is serious libertarian.

When Paul allowed as how he might have a problem with the critical components of the Civil Rights Act of 1964—in a terrific interview by MSNBC’s Rachel Maddow—it suddenly started to dawn on Democrats and Republicans that a relatively genuine libertarian had been nominated by one of the major parties for a major position.

The thing about libertarianism is that it is an ideology that both Democrats and Republicans like to borrow from—liberals like the live-and-let live approach to social policy, conservatives like all the talk about deregulation and downsizing government.

It is only when the whole package gets pulled together that things get hairy.

And Rand Paul really is his father Ron’s son—which means that he is very serious about economic libertarianism, pretty serious about maintaining a classic libertarian non-interventionist foreign policy and pretty shaky when it comes to social libertarianism (especially when it comes to reproductive rights).

In other words, like Ron Paul, Rand Paul is a grab-bag libertarian who offers everyone something to like and something to decry.

Just as progressives delighted in Ron Paul’s anti-imperialist diatribes in the Republican presidential debates of 2007—especially when the Texas congressman’s discussion of Chalmers Johnson’s theory of blowback made Rudy Giuliani blow up —there have always been plenty of diehard conservatives who perked up when the elder Paul proposed shutting down whole sectors of the federal government.

But just as oil and water do not go together very well, it is not always easy to mix Noam Chomsky–quoting foes of empire with Milton Friedman–quoting foes of public education.

So the libertarian movement has always remained small. There really are true believers in the ideology, and the Pauls (father and son) come pretty close—so close, in fact, that the father left the GOP in 1988 to seek the presidency as the nominee of the Libertarian Party. Ron’s message that year was as critical of Republicans as it was of Democrats, with the formerly Republican congressman declaring that “big government is running away with our freedom and our money, and the Republicans are just as much to blame as the Democrats.” Of GOP icon Ronald Reagan, the elder Paul said: “Ronald Reagan has given us a deficit ten times greater than what we had with the Democrats. It didn’t take more than a month after 1981, to realize there would be no changes.”

Ron Paul was right, as he was when he told a convention of the National Organization for the Reform of Marijuana Laws that the war on drugs was a failure. And who could argue with the Libertarian Party platform proposal to included the removal of all US nuclear weapons from Europe. But Paul’s preaching about the need to return to the gold standard got a bit arcane. And Rand Paul got arcane with his dad; serving as the elder Paul’s chief campaign aide and frequent spokesperson and representative.

The campaign did not go very far, however. Ron Paul won only 431,750 votes—for a little less than 0.47 percent of the vote. (In Sarah Palin’s Alaska, the Libertarians took over 2 percent that year, but that was the high-water mark.)

The disappointing 1988 result was about as good as its gotten for Libertarians in the past quarter century. And the Pauls recognized pretty quickly that, if they wanted to actually win elections, they would probably have to do so as Republicans.

Ron Paul scrambled back into the GOP fold quickly, supporting Pat Buchanan’s Republican presidential bid in 1992 and getting re-elected to Congress—over the objections of the party leadership—in 1996.

In Congress, Ron Paul has served as a caucus of one, regularly casting solo votes against legislation that the rest of the House backs. He’s not always alone. But he is frequently at odds with the Republican caucus and sometimes more in sync with the most left-wing Democrats than with the most right-wing Republicans—but only sometimes.

Rand Paul has made a point in this campaign year of suggesting that he differs with his dad on some key issues; but the fact is that the younger Paul’s Senate run was managed and funded by many backers of the father. They are dedicated, true-believer libertarians who have accepted, as the Paul’s have, that there is more room to maneuver in the Republican Party than on the third-party fringe.

The problem, of course, is that there is a reason why the Libertarian Party has remained on the fringe.

Yes, it has suffered as a result of the same unfair ballot-access laws and debate designs that have afflicted other third parties. But it also entertains ideas that that are outside the mainstream.

The libertarian ideology may have its day. But that day has not yet come.

For now, serious libertarians are ideological outliers—committed to their views and sincere in their approach but outliers all the same.

And when an outlier enters the mainstream, fireworks ensue.

That’s the bottom line with regard to Rand Paul: Try as he may to steer toward the center, that’s not where his heart or head is. And, as a result, he will keep saying things that send shock waves through the political mainstream.

That may be a good thing, in that it forces deeper and broader debates. But it is going to cause a lot of headaches for Rand Paul and his adopted Republican Party.