Susan Rice, the U.S. ambassador to the United Nations who came under fire after repeating inaccurate information about the Benghazi embassy attacks, withdrew her bid Thursday to be the next Secretary of State. In a letter to President Obama, who was expected to nominate her for the post Hillary Clinton is leaving after four years, Rice said she is convinced her confirmation process “would be lengthy, disruptive and costly,” a clear reference to Republican attacks on her regarding Benghazi. But there may have been other factors as well.

Score at least one point for John McCain: After the Arizona senator (and 2008 election loser) loudly protested the prospect of Rice’s nomination, it looks like he won. A spokesman for McCain said the senator “thanks Ambassador Rice for her service to the country and wishes her well.”

The Benghazi issue was the largest of the several concerns Rice’s critics had about her fitness for the job. But there were plenty of others raised from across the political spectrum. On Nov. 28, On Earth, the magazine of the Natural Resources Defense Council, broke the news that Rice held stock in Canadian banks and companies that would stand to benefit from the proposed Keystone XL pipeline between Canada and the United States. The State Department nixed the deal in 2011 after environmental groups protested.

Around the same time stories were leaking out in various outlets depicting Rice as temperamentally unfit to be Secretary of State—specifically that she was too blunt and outspoken for a job that regularly requires a delicate and diplomatic hand.

Finally, it appeared likely that Rice’s record as Assistant Secretary of State for African Affairs in the Clinton administration would come under renewed scrutiny—in particular her role in the U.S. response to the 1994 genocide in Rwanda. As Samantha Power recounted in her book on the genocide, “A Problem From Hell,” Rice—who served on Clinton’s national-security council at the time—was concerned about the political ramifications for the upcoming midterm elections if the United States called the slaughter a genocide and then did nothing.

Since Rwanda, Rice embraced the tradition of liberal internationalism. When Muammar Gadhafi threatened in 2011 to wipe out Benghazi, Rice led the charge at the United Nations—and inside the Obama administration—for a U.S.-led air war to save Libya’s second city.

So it was somewhat ironic that events in Benghazi would end up costing Rice her shot at becoming America’s top diplomat. Slowly but surely, McCain picked up members of his own party to oppose Rice on the grounds that she had appeared on Sunday talk shows and mischaracterized the Sept. 11 attacks in Benghazi as the result of a spontaneous riot, rather than a terrorist attack executed by groups linked to al Qaeda. Earlier this month when Rice met with McCain and other senators, the back and forth had no effect. Her failure to win over Sen. Susan Collins, one of the most moderate Republican voices in Congress, was a particularly ominous sign.

Heather Hurlburt, the executive director of the National Security Network, a think tank with close ties to the White House, said the Republican’s successful opposition to a U.N. treaty on disabilities was an ominous sign for the Rice nomination. That opposition carried the day even as former senator Bob Dole, who lost the use of his right arm after he was shot by a German machine gunner in World War II, appealed to his party to support the treaty.

“When you see there is enough of the Republican party that is willing to stick a knife in Bob Dole in order to stick a knife in the United Nations, you had to take a really cold look at Ambassador Rice’s chances,” Hurlburt said. “I think that’s what Obama did.”

Rice’s exit now clears the path for John Kerry, the Massachusetts senator who lost the 2004 election to George W. Bush. It’s no secret in Washington that Kerry covets the top job at the State Department, but the downside to his appointment for Democrats is that the Republicans would have a chance at picking up his seat. The last open seat in Massachusetts went to Republican Scott Brown, who lost his re-election in November to Elizabeth Warren, a Democrat.