Secretary of State Hillary Clinton remains hugely popular in national polls. (Brendan Hoffman/GETTY IMAGES)

A new Gallup poll finds that 66 percent of Americans have a favorable view of Secretary of State Hillary Clinton, up from 61 percent in July 2010 and approaching the highest numbers ever for the former New York senator.

Those numbers make Clinton considerably more popular than President Barack Obama (54 percent favorable) and Vice President Joe Biden (46 percent.)

And, while as a Cabinet member Clinton is under far less partisan scrutiny than the president himself, Clinton also polls better than Defense Secretary Robert Gates.

“Because she is working as a loyal and diligent part of the Obama administration, she has the unified support of Democrats,” said Mark Penn, a pollster who worked with Clinton’s presidential campaign. “On top of that she is seen as showing particular strength on behalf of the national interest; that also brings her widespread support from independent voters and even some Republicans.” 

Numerous surveys over Clinton’s tenure as the U.S.’s top diplomat have shown similar strong results, and each time they’ve stoked interest in what — if anything — the political future holds for Clinton. (A Gallup poll last November even found a third of Democrats hoping she would challenge President Obama in 2012.)

Clinton has insisted — recently and at several other points during her time at State that she will not serve as second term in her current role, has no interest in other jobs within the Obama Cabinet and will not seek political office again in her lifetime.

And, while a cursory look at these numbers will almost certainly buoy those arguing that she should consider a 2016 run for president, there’s reason for skepticism that she would be able to sustain such lofty polling heights if she returned to the partisan political arena.

A look back the recent polling history of Secretaries of State suggests it is a widely admired position — no matter who holds the office.

Condoleezza Rice often polled twenty points above President George W. Bush. Her numbers stayed in the high 50s throughout her tenure, even as she underwent grueling Capitol Hill hearings over the Bush administration’s actions abroad. Madeline Albright was about as popular as then President Bill Clinton; Colin Powell was even more popular than his president, with approval ratings in the 80s.

All four of these cabinet secretaries may have benefited from reputations as trailblazers as well. Albright was the first female secretary of state. Powell was the first African-American secretary of the state. Rice was the first female African-American to hold the job, and Clinton was close to being the first female president.

And, while it’s easy to look at Clinton’s stratospheric approval numbers today and extrapolate out to another presidential bid, it’s likely that if she did choose to run again many people who support her now would begin seeing her through a more partisan lens and find her wanting.

In the Gallup data, four in ten Republicans have a favorable opinion of her. It’s virtually impossible to imagine those numbers not plummeting if she re-entered the political world.

Clinton has an example of that polling phenomenon in her own household. After leaving the presidency, Bill Clinton saw his popularity numbers soar. But, his deep — and, at times, controversial involvement in his wife’s 2008 campaign caused an extended dip in his favorable ratings. Once the campaign ended, however, Bill Clinton’s numbers returned to their previously high levels.

Friends of Clinton insist she should be taken at her word that there will be no more races in her future — no matter how popular she becomes.

“Honestly, I think shes looking forward to another chapter of her life,” said Terry McAuliffe, Clinton’s 2008 campaign chairman. “I think shes looking forward to finishing up this term...I don’t want to step on any toes here, but hopefully maybe she’s a grandmother by then. I could see her enjoying life.”