Sen. Rand Paul (R-Ky.) greets the crowd as he arrives...

Sen. Rand Paul (R-Ky.) greets the crowd as he arrives to announce the start of his presidential campaign, Tuesday, April 7, 2015, at the Galt House Hotel in Louisville, Ky. Credit: AP / Carolyn Kaster

Sen. Rand Paul's newly announced candidacy for president prompts the slippery question of how to define a libertarian.

Talkers toss the word around in discussions of where the Kentucky Republican may find support and of how he measures up on issues against his father, Ron Paul, the former congressman who once ran for president as the Libertarian Party candidate and later in GOP primaries.

Liberty is supposed to be a founding ideology of the republic. So on some level, Americans are all presumed to be libertarians.

In Washington and news-media jargon, however, the word is often used to describe a faction of the right. Insiders often view self-proclaimed libertarians as seeking, recklessly or naively, to erase modern government institutions, overseas interventions and business regulations.

Mark Axinn, chairman of the Libertarian Party of New York, casts a different light on the label.

In New York City, he said, the party has had success attracting citizens' signatures on qualifying petitions by stating opposition to random police stop-and-frisk practices. "That's a different manifestation than [overseas] bombing, but also a manifestation of government run amok," he said. The party also has done well gathering signatures in places such as Coney Island by touting support for legalizing marijuana, Axinn said.

Lefty-liberal libertarianism (say that three times fast!), if such a term is valid, seems to occupy a different spatial dimension from Rand Paul's pronouncement in Louisville Tuesday that the Cold War saw "the engine of capitalism finally winning out against the sputtering, incompetent engine of socialism."

On abortion rights and same-sex marriage, opponents and backers alike constantly strive to portray themselves as on the stronger libertarian ground.

Given all that, you may well come up short when asking who the libertarians are.

Michael McDermott, the Suffolk Libertarian Party chairman, who ran for governor on the line last year, slams two-party, left-right labels that "box us into a particular mindset."

"We believe in individual liberty -- to do what you want as long as you don't interfere with the rights of others. And we believe in the Constitution," said McDermott, a Huntington resident.

State Libertarian chairman Axinn said: "If the Republican Party was made up of all Rand Pauls, I'd be delighted to talk to the Republican Party. But at the end of the day, he's a Republican. And while he's taken some good positions -- for example, on NSA spying and the collection of metadata -- he's also supported foreign interventions and global world-building."

But in trying to win Republican primary voters, Paul must walk tightropes. On drone usage, he recently said he only protests their use in "a targeted killing ordered against a U.S. citizen on American soil."

Axinn, of course, plans to support the Libertarian candidate, who last time was Gary Johnson, the former Republican governor of New Mexico.

Paul used the word "liberty" eight times in Tuesday's announcement, "freedom" nine.

In 2013 Paul was quoted as saying, "I'm not a libertarian. I'm a libertarian Republican. I'm a constitutional conservative." In 2010 he told Time magazine of rivals: "They thought all along that they could call me a libertarian and hang that label around my neck like an albatross, but I'm not a libertarian."