PHOENIX — U.S. Sen. John McCain (R-Ariz.) said Friday he would not vote for the Republican Party’s latest attempt to repeal Obamacare because it was not the result of a bipartisan effort.

“I cannot in good conscience vote for the Graham-Cassidy proposal,” McCain said in a statement. “I believe we could do better working together, Republicans and Democrats, and have not yet really tried.”

The senator also said he objected to the Senate bill because it was not subject to debate, amendments and review by the nonpartisan Congressional Budget Office.

“I [could not] support it without knowing how much it will cost, how it will affect insurance premiums, and how many people will be helped or hurt by it,” he said. “Without a full CBO score, which won’t be available by the end of the month, we won’t have reliable answers to any of those questions.”

McCain compared the bill to Obamacare, saying it relied on party lines for passage and would not create a lasting solution.

“Our success could be as short-lived as theirs when the political winds shift, as they regularly do,” he said.

“The issue is too important, and too many lives are at risk, for us to leave the American people guessing from one election to the next whether and how they will acquire health insurance.”

McCain’s decision to not back the bill put him at odds with Gov. Doug Ducey, who supports it.

Two months ago, McCain’s no vote sank another Republican attempt at repealing Obamacare. McCain worked closely with the governor in the days leading up to the vote.

The latest effort to repeal Obamacare was sponsored by Sens. Lindsey Graham (R-S.C.), Bill Cassidy (R-La.), Dean Heller (R-Nev.) and Ron Johnson (R-Wisc.), some of McCain’s closest allies in the Senate.

Studies said the bill would hit states that have expanded Medicare, such as Arizona, the hardest. A study from consulting firm Avalere Health estimated the state would receive about $133 billion less in federal funding under the latest health care plan.

The left-leaning Center for American Progress estimated about 511,000 Arizonans would lose health care coverage.

Arizona’s junior senator, Jeff Flake, told “The Late Show with Stephen Colbert” earlier this week that he supported the bill. He believed it would be a narrow vote, but thought the bill would pass.

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