WASHINGTON - To this point, Sen. Rand Paul of Kentucky has been the Republican flavor of the year. Events from the IRS scandal to NSA revelations to the Obamacare train wreck have corroborated libertarian suspicions of federal power. And Paul has shown serious populist skills in cultivating those fears for his political benefit.

For a while, he succeeded in a difficult maneuver: Accepting the inheritance of his father's movement while distancing himself from the loonier aspects of his father's ideology.

But now Rand Paul has fallen spectacularly off the tightrope. It turns out that a senior member of his Senate staff, Jack Hunter, has a history of neo-Confederate radio rants. And Paul has come to the defense of his aide.

Paul's attempt to dismiss the matter has only added to the damage. "It was a shock radio job," the senator explains. "He was doing wet T-shirt contests. But can a guy not have a youth and stuff? People try to say I smoked pot one time and I wasn't fit for office."

But Hunter's offenses were committed as an adult. They included defending a regime founded on slavery, comparing Abraham Lincoln to Saddam Hussein, and raising (in Hunter's words) a "personal toast every May 10 to celebrate John Wilkes Booth's birthday." This was not a single, ideological puff, but a decade spent mainlining moonlight and magnolias in the ruins of Tara.

Paul is rumored to be considering a 2016 presidential run. So his dismissal of the sympathetic treatment of a presidential assassin as the equivalent of sponsoring a wet T-shirt contest requires some explanation. The easier political course for Paul would have been to cut this embarrassing tie and reduce the damage.

This would not be the first time Paul has heard secessionist talk in his circle of associates. His father has attacked Lincoln for causing a "senseless" war and ruling with an "iron fist." Others allied with Paulism in various think tanks and websites have accused Lincoln of mass murder and treason. For Rand Paul to categorically repudiate such views and would be to excommunicate a good portion of his father's movement.

This disdain for Lincoln is not a coincidence. Paulism involves more than the repeal of Obamacare. It is a form of libertarianism that categorically objects to 150 years of expanding federal power. During this period, the main domestic justification for federal action has been opposition to slavery and segregation. Lincoln, in the Paulite view, exercised tyrannical powers to pursue an unnecessary war. Similarly, Paulites have been critical of the 1964 Civil Rights Act for violating both states' rights and individual property rights -- an argument Rand Paul himself echoed during several interviews as a Senate candidate.

This does not make Paulites racists. But it does make them opponents of the legal methods that ended state-sanctioned racism.

To put the best construction on it, Paulites tend to hate war and federal coercion in any form, even in causes generally regarded as good. They opposed the Cold War and nearly every post-World War II American exercise of power. They equate the war on terrorism with militarism, imperialism and empire. And they remain unhappy about the War of Northern Aggression.

Not all libertarians view Appomattox as a temporary setback. A libertarian debate on the topic: "Lincoln: Hero or Despot?" would be two-sided, lively and well attended. But Paulism is more than the political expression of the Austrian school of economics. It is a wildly ambitious ideology in which Hunter's neo-Confederate views are not uncommon.

What does this mean for the GOP? It is a reminder that, however reassuring his manner, it is impossible for Paul to join the Republican mainstream. The triumph of his ideas and movement would fundamentally shift the mainstream and demolish a century and a half of Republican political history.

The Hunter matter is a reminder that Paul is a conviction politician. His convictions are the problem. In January, Hunter wrote that the "philosophy hasn't substantively changed" between Ron Paul and his son. Rand Paul's goal is to legitimize the Paulite movement, not repudiate its worst elements. But his ties to those elements may put an upward limit on his political rise.

Washington Post Writers Group