Like many VIPs in New York Republican circles, Michael Long will be very busy this week. As he does at every GOP convention, Long plans to hop from event to event and spend some time on the Madison Square Garden floor with the Empire State delegation.

But Mike Long isn’t an elected official or a high roller. He doesn’t work in any of New York’s major industries. He conducts most of his business from a liquor store in Bay Ridge — the Brooklyn neighborhood where “Saturday Night Fever” was set.

Most notably, Long isn’t even a Republican. He is the chairman of the New York Conservative Party, a small but powerful entity that has influenced state, and occasionally national, politics for four decades.

“The Conservative Party is very important, especially at the local level in New York,” said a national Republican strategist with close ties to the Empire State. “The [state] Senate races, the Assembly races — there are very few competitive races. In the ones that are, the Conservative nomination is very, very important.”

Ronald Reagan spoke at the party’s annual dinner in 1975. Every Republican presidential nominee has asked for, and received, the Conservative ballot line since 1972. President Bush’s campaign chairman, former Montana Gov. Marc Racicot (R), will speak at a Conservative cocktail party in late September. Sen. Zell Miller, the conservative Georgia Democrat, headlined the party’s annual dinner in June.

Thanks to New York’s unique election laws, minor parties are able to either run candidates of their own or endorse major party nominees. This gives third parties far greater leverage in New York than their size would otherwise warrant.

Some are driven by ideology or personal agendas. Others become vessels for patronage. Under Long, the Conservative Party has become a blend of the two.

“Some people know how to thrive in” the New York electoral system, said Ray Harding, boss of the now-defunct New York Liberal Party. And Long, he says, “is one of them.”

The Independence Party, an offshoot of Ross Perot’s old Reform Party, has the “third column” on New York’s ballot this cycle, based on the votes for governor won by Rochester billionaire Thomas Golisano in 2002. But while the Conservative Party slipped to the fourth column two years ago, it remains the party with the most influence.

Founded in the early 1960s as a counterpoint to then-Gov. Nelson Rockefeller’s liberal Republicanism, the Conservative Party has sought to check on the state GOP ever since, exhorting Republican leaders to move to the right, and threatening and punishing those who do not. No Republican has won statewide office in New York without the Conservative nomination since 1974.

“Republicans sometimes forget that the Conservative Party was founded as an outlet to keep Republicans honest,” said George Marlin, author of a history of the party and the Conservatives’ 1993 nominee for mayor of New York. “We can provide the margin of victory, or the margin of defeat.”

Harding said while the Conservative Party “is not a subsidiary [of the GOP], in certain respects it is the tail wagging the [Republican] dog.”

Some high points in the party’s history include the 1965 New York mayoral election, in which William F. Buckley Jr.’s improbable candidacy galvanized national conservatives who were still smarting from Barry Goldwater’s landslide defeat in the presidential election the year before. In 1970, Buckley’s brother, James, won a U.S. Senate race on the Conservative line with just 39 percent of the vote. And in the 1980 Senate race, Conservative Party support helped push a little-known Long Island official named Al D’Amato across the finish line against veteran Republican Senator and Rockefeller ally Jacob Javits.

Since then, the Conservatives have aided Republican Gov. George Pataki’s ascent and have complicated former New York Mayor Rudy Giuliani’s calculations for higher office by repeatedly calling him a liberal. (This antagonism has waxed and waned; when Giuliani, in the aftermath of the Sept. 11, 2001, terrorist attacks, searched for ways to skirt the city’s term-limit laws, Long considered offering him the Conservative line in the 2001 mayoral race.)

For the past few years, the party has been led by Long, who conducts much of the Conservatives’ business from the cash register at Long’s Discount Wines & Liquors in Bay Ridge, just down the street from the party’s state headquarters. If politics interfere with business, he’ll turn the counter over to someone else and step outside, leaning on a parking meter as he converses.

“Mike Long is truly the streetcorner conservative,” Marlin said.

Although the Conservative Party essentially feeds off the GOP, Long has roiled Republicans several times in recent years. His criticism of Republican leaders in the state Senate has been merciless, decrying their votes for tax increases and a statewide ban on smoking in restaurants and bars.

And this year, the Conservatives turned their back on the state GOP’s handpicked nominee for U.S. Senate, state Assemblyman Howard Mills. The party instead gave its line to Long Island ophthalmologist Marilyn O’Grady, who made national headlines recently by advocating a boycott of Bruce Springsteen’s albums because of the rock star’s criticisms of Bush.

“It’s odd that there’s been so little commentary about their little rebellion in the New York Senate race,” said Richard Winger, publisher of “Ballot Access News,” which chronicles third-party developments around the country. “It seems as if they’re going back to the way they were in the 1960s.”

Long has described Mills as too liberal to merit the Conservative line, though he has run for state and local office with Conservative backing. But the consequences for the GOP could be embarrassing.

While Mills never has been given any chance of beating Sen. Charles Schumer (D-N.Y.), a recent poll showed the Senator taking 62 percent, Mills 13 percent, and O’Grady 9 percent.

“We’ll assume Schumer is going to be re-elected,” Marlin said. “The real issue is who’s going to come in second.”

If Long is sweating the implications for the state GOP, he isn’t saying.

Admirers describe Long as ideologically pure and a straight shooter who never is afraid to speak his mind.

“He’s smart, he’s independent, he’s principled and his word is his bond,” Harding said.

But others complain while Long has been happy to criticize some Republicans like Giuliani and state Senate Majority Leader Joseph Bruno, he has been silent when Pataki espouses moderate social positions or forms alliances with liberal labor unions. Long — whose sons own taverns and were directly affected by the smoking ban — was also gentle on Pataki when the governor quickly signed the bill into law.

Politicos have a theory for the apparent double standard: One of Long’s daughters until recently held several high-profile positions in the Pataki administration. And they hint that Long’s decision to back O’Grady for Senate may have less to do with his distaste for Mills than his desire to placate O’Grady’s political patron, Nassau County Conservative Chairman Roger Bogsted. Bogsted is often described as the one person who could credibly challenge Long for the statewide chairmanship some day.

What’s ahead for the Conservative Party may depend, in some respect, on what happens to the New York Republican Party once Pataki exits the stage. Some rank-and-file party members see Long’s decision to back O’Grady as a hopeful sign that the party will run its own slate of candidates against the Republicans in the 2006 state elections. Other observers say any rebuilding of the state GOP will have to include discussions with the Conservative Party.

Long himself says it’s way too early to discuss 2006. He won’t even discount the possibility of backing the party’s nemesis, Giuliani, in the future.

Despite Long’s ideological purity, politics inevitably play a part in every calculation he makes. If the candidate the Conservative Party endorses for governor in 2006 fails to get at least 50,000 votes, the party loses its official status — a fate that sank the Liberal Party two years ago. As one New York political insider puts it, “They’re always one election away from obscurity.”