Hillary Clinton, who put 18 million cracks in the glass ceiling in her race to be the first woman to hold the presidency, said yet again that she is done with politics when her tenure as Secretary of State ends next year.

The former U.S. Senator and first woman to win a state's presidential primary election, told her staff that she is ready to get off the high wire of American politics when she leaves the White House, even if President Barack Obama wins re-election. She said she will remain in Obama's cabinet until he picks a new secretary of state and a transition can begin.

I think after 20 years, and it will be 20 years, of being on the high wire of American politics and all of the challenges that come with that, it will be probably be a good idea to find out how tired I am, she said Thursday.

Clinton, 64, left a door cracked ever-so-slightly for a political return, noting that everyone always says that when they leave these jobs.

Her comments followed a question about joining Obama, 50, on the 2012 ticket as the vice presidential nominee. Even if the idea is mocked as a political fantasy, swapping out Vice President Joe Biden, 69, for Clinton has been pushed as a way to bolster Obama's re-election chances and give Clinton a launching pad for a 2016 presidential campaign.

But, as she often does when presented with the scenario, Clinton praised Biden.

I am happy to work with Vice President Biden, who does an excellent job and is a huge advocate and supporter for this department, she said.

It's a little odd to be totally out of the election season, since as Secretary of State I cannot participate, but you know I didn't watch any of those debates, she added.