The three-month-old controversy over the attack on the U.S. diplomatic post in Benghazi, Libya, has laser-focused on Susan Rice, the U.N. ambassador and the most likely pick to succeed Hillary Clinton as secretary of state.

And right now, Rice needs Clinton on her side.

Unfortunately for her, Clinton has about every reason to stay away from the situation.

Hillary Clinton adjusts her translation device during a news conference at the U.S. embassy in Nairobi. (Thomas Mukoya -- Reuters)

Clinton offered some praise for Rice late last week, but some saw the words as a little tepid.

"Susan Rice has done a great job as our ambassador to the United Nations,” Clinton said Wednesday. “Of course, this decision about my successor is up to the president, but I am very happy he has the opportunity with a second term to make a decision.”

Contrast that to President Obama's own proclamation at a Cabinet meeting last week, in which he said: "Susan Rice is extraordinary. I couldn't be prouder of the job that she's done."

Rice has been by far the biggest focus in the postmortem of the attack in Benghazi, in which four Americans, including the U.S. ambassador to Libya, were killed. Clinton said back in October that she herself was responsible for the diplomats' security as head of the State Department, but the controversy has instead centered around Rice and the version of events she offered on the Sunday talk shows after the attack.

Rice suggested at the time that the attack grew out of a spontaneous protest triggered by an anti-Islam video. But the administration later called it an act of terrorism, though one that may have been hastily organized.

The White House and senior intelligence officials have said her statements in the days after the attack followed approved talking points, including vague wording designed to conceal intelligence information.

Republicans have eviscerated Rice for what she said on the talk shows, and for the past week or so especially, she has been treading water (she earned our "Worst Week in Washington" designation last week).

The reasons Rice needs Clinton and Clinton doesn't need Rice are one and the same: Clinton is very popular.

Few public figures have anywhere near Clinton's popularity right now. Most recent polls -- including one as recently as two weeks ago -- show her earning the approval of about two-thirds of Americans. Despite her past as a polarizing political figure, she has built a rock-solid political brand that is both a huge asset in advance of a possible 2016 run and a potentially huge benefit to Rice if she gets Clinton's seal of approval.

But Clinton has plenty of reasons to stay away. Here are three that are chief among them:

1. To this point, Clinton has been essentially unscathed by the controversy. Even as Rice and the White House have paid a price, Clinton really hasn't. Involving herself more publicly could turn the spotlight on her own role or at least associate her more with the controversy. She is about to retire after a hugely successful tenure at the State Department and potentially move toward another presidential run, and stepping into this battle could leave the kind of blemish on her record that she has somehow managed to avoid so far.

(Indeed, by focusing so intently on Rice, Republicans have basically let Clinton be in recent weeks, perhaps choosing momentary political gain over helping their prospects in 2016 -- or simply recognizing that Clinton is frankly a much tougher target.)

2. Rice left the Clintons. She once worked in Bill Clinton's administration, but she was one of the first former Clinton aides to jump ship to Obama's campaign when he ran in 2008 and was highly critical of Hillary Clinton's positions on Iraq and Iran. And as we've written before, nobody keeps score like the Clintons

Administration sources say old rivalries are just that -- old -- and they note that Obama and Clinton have formed a solid alliance after their brutal 2008 primary. They say Rice and Clinton are on good terms and meet weekly. 

3. Clinton is rumored to prefer Sen. John Kerry (D-Mass.) for the job. This makes sense. Clinton served in the Senate with Kerry before becoming secretary of state. And if Rice for whatever reason doesn't get the job, it could mean Kerry becomes Clinton's successor.

It remains to be seen whether Clinton weighs in further in the coming days. Senior administration aides told The Fix that she has made calls to members of Congress to stick up for Rice.

Clinton spokesman Philippe Reines called The Fix's inquiry "utterly baseless and manufactured to create conflict where none exists."

"As the Secretary has said, she thinks the Ambassador has done a great job," Reines said. "The entire administration is focused on finding out what happened in Benghazi, doing all we can to protect our diplomats abroad, and bringing those responsible for killing four Americans to justice. That's what matters."

For now, Clinton remains unscathed, and Rice remains in trouble.