Now that Hillary Clinton is the presumptive nominee of the Democratic Party, the United States is facing the real possibility of a female president for the first time ever. (!) With that potential change comes a million questions about how the White House might operate differently under a female commander-in-chief, including the persistent, and interesting, question of the First Lady. Who would be Hillary Clinton's First Lady if she becomes president? Without any precedent whatsoever, the Clintons are going to have to figure it out for themselves.
There are two primary contenders for the role of First Lady in a potential Hillary Clinton administration: Bill Clinton and Chelsea Clinton. Technically, the First Lady isn't the spouse of the President, it's the "hostess of the White House." That's why there was never much debacle when a single man like Grover Cleveland or a widower like Woodrow Wilson was in office — a female relative, like President Cleveland's sister Rose Elizabeth Cleveland or President Wilson's daughter Margaret Wilson, would step in to fill the position.
Theoretically, the same might apply in a Hillary Clinton White House. Experts are speculating that Chelsea Clinton may be the heir apparent to the position, making her the first First Lady to ever serve under two different presidents (she served out the final days of her father's presidency when her mother abdicated the role due to a conflict of interest from her newly-won Senate seat.)
Of course, there are a few differences between the historical role of the First Lady and what the position currently entails. The gendered aspect of the role has significantly diminished as recent First Ladies like Michelle Obama and Hillary Clinton herself have largely dedicated their efforts to policy campaigns and a more active style of public service. Bill Clinton should be more than capable of maintaining the duties of the First Lady under a different title, such as First Husband or First Gentleman, like the husbands of the former prime minister of India Indira Gandhi and president of the Philippines Corazon Aquino.
If Clinton is elected as the first female president, the redefinition of the role of First Lady will certainly be part of her enduring legacy. The Clinton family will need to come together to figure out to decide how best to precede into this uncharted territory, keeping in mind the hopefully many female presidents to come. Figuring out this change won't be easy, especially considering the volatile attitude some pockets of American society have towards shifting gender roles, but if a woman can win the election, she can definite figure out how to navigate this adjustment.