The state party approved a resolution Saturday censuring McCain for a Senate record it called "disastrous and harmful."
It said he had a "long and terrible record of drafting, co-sponsoring and voting for legislation best associated with liberal Democrats."
McCain, 77, told Politico the state party's comments were "regrettable" but not politically damaging. He pointed to poll numbers that suggest strong voter backing.
"We've got polling data that shows overwhelming support. I've won every election in Arizona by very large margins, quite often with the opposition of that element of the party," McCain said, referring to the state's rightward flank, which he called a "very small portion" of Arizona voters.
"If anything, it fires me up," he said of the censure.
McCain is considering a sixth Senate term in 2016. He first ran in 1986, succeeding longtime conservative Sen. Barry Goldwater on his retirement.
The state GOP censure cited McCain for funding the Affordable Care Act, informally known as "Obamacare."
The senior senator from Arizona, who has strongly opposed the landmark healthcare legislation, called that hit to his record "bizarre."
"I led the fight for 25 days on the floor of the Senate," McCain said of his opposition to the healthcare law's December 2009 Senate passage.
On March 22, 2010, the day before President Obama signed the legislation, he told an Arizona radio station he also opposed the way the measure had been handled in Congress.
"There will be no cooperation [with Democrats] for the rest of the year," he said. "They have poisoned the well."
McCain last year strongly went up against a conservative-led strategy of opposing any federal government spending bill that funds the healthcare law, predicting the tactic would result in a government shutdown that would be blamed on Republicans.
The government shut down Oct. 1-16.
"I know how the movie ends: We don't defund Obamacare until we have 67 Republicans in the United States Senate," he said Sept. 30, 2 hours before the shutdown.
"We can't win," he told reporters in the Capitol.
"Republicans will be perceived as blocking and as shutting down the government," he said.
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