NEW YORK (AP) — The state Independence Party endorsed Republican John McCain on Saturday, the first time New York’s third-largest party has backed a major-party presidential candidate.

The group, organized around the principle that the major parties have a stranglehold on American politics, sees McCain as an independent thinker, Chairman Frank MacKay said.

“I believe he will not take the traditional input from the party bosses and the special interests that other presidents have. I believe he’s going to be his own man,” MacKay said, citing McCain’s work as co-author of a landmark 2002 law that restricted “soft money,” or indirect campaign donations.

McCain’s campaign and that of Democratic presidential hopeful Barack Obama did not immediately respond to telephone and e-mail messages Saturday night.

Supporters of independent presidential candidate Ross Perot founded New York’s Independence Party in 1996. It now counts about 355,000 registered voters statewide, compared to more than 5.4 million Democrats and nearly 3 million Republicans. The state also has more than 2.3 million unaffiliated voters.

The Independence Party has endorsed some of the state’s prominent Democrats, including Sen. Hillary Rodham Clinton and former Gov. Eliot Spitzer. But it also has displayed the autonomous streak its name suggests, supporting Ralph Nader for president in 2004 and little-known White House contender John Hagelin in 2000.

MacKay said the party had long admired McCain, who has emphasized his reputation as a party-bucking maverick and striven to present himself as a reformer on the campaign trail.

The Arizona senator has, however, voted with President Bush 90 percent of the time since January 2001, according to a Congressional Quarterly study. MacKay dismissed that finding as “wordplay.”

The Independence Party’s platform includes ending budget deficits, changing campaign finance laws to limit donors’ influence and discouraging teenage pregnancy, according to its Web site.