First lady Michelle Obama is celebrating her 50th birthday with a blowout dance party. Here's a look at some of her best moves and grooves. (Julie Percha/The Washington Post)

For anyone — but especially for a woman — a 50th birthday is a moment for coming to terms with a life.

Coming to terms with what it is, as measured against what she had hoped it would be. Reconciling options that have been closed with what it would take to try the ones that are left.

Michelle Obama has reached that milestone with what from all appearances is unalloyed jubilation. Her declaration that she is “50 and fabulous” is an understatement, given how saucily she waves her new AARP card. And there is no end to speculation as to what the next chapter will be, because — for her — just about anything seems possible.

To get a real sense of what is possible, in politics and in life, for a woman on the latter side of midlife, it is worth considering the last first lady who marked that bittersweet birthday in the White House.

When Hillary Rodham Clinton turned 50 on Oct. 26, 1997, she carried the not-yet-healed bruises from having nearly run her husband’s presidency aground.

Her 50th birthday came just three years after her politically disastrous effort to overhaul the health-care system. Clinton had spent the first two of them in a sort of political exile, rarely venturing into the West Wing, and choosing her public appearances carefully. Even her wardrobe had undergone a shift, from teals and reds and blacks to pastel suits, with pumps to match.

“She was trying to figure out how she could be who she is — a thinker, a doer — without arousing hostility from those who felt she was overstepping her bounds,” her longtime confidante Diane Blair told Time magazine at the time.

Being first lady is a position that comes with no job description, and the tripwires can be hard to see.

What Michelle Obama and Hillary Clinton also share is the fact that each has been an emblem, as well as a first lady — Obama, as the first African American to have the role, and Clinton, as a symbol for a generation of women coming of age as feminists.

Where Obama wears that burden as though it is weightless, Clinton at 50 was still struggling with it.

“There is no formula that I’m aware of for being a successful or fulfilled woman today,” Clinton had once said. “Perhaps it would be easier . . . if we could be handed a pattern and just cut it out, just as our mothers and grandmothers and foremothers were.”

Clinton was also struggling with letting go in her personal life. Her daughter had headed to a college nearly 3,000 miles away, leaving the white, pillared nest empty. Aide Melanne Verveer caught Clinton looking through a book called “Internet E-Mail for Dummies.”

Around the time that Bill started needing hearing aids, Hillary was musing about adopting another child.

As 50 approached, she had also begun to take a few steps toward political rehabilitation.

As muted as she was at home, Clinton was finding her voice overseas. Later, as secretary of state, she would celebrate the moment when she declared in Beijing that “it is no longer acceptable to discuss women’s rights as separate from human rights.” She was called “Sister Hillary” in Senegal, and in Bangladesh, a village was named for her.

In 1996, her book “It Takes a Village” became a bestseller and helped to redefine her.

Still, when she reached 50 the public scandal over Monica Lewinsky, which would send sympathy for the first lady soaring, was still in the future.

Public humiliation was a huge price to pay for an opportunity. But on the very day in February 1999 that the Senate was voting to acquit Bill Clinton in his impeachment trial, Hillary Clinton — age 51 — was huddling with adviser Harold Ickes back at the White House, giving Ickes the go-ahead to begin laying the groundwork for a Senate campaign in New York.

She won it easily — twice — but fell short against Michelle Obama’s husband when she reached for the next rung in 2008. In her 60s, she reinvented herself yet again, as the loyal team player for her onetime rival.

The week the current first lady turns 50, the cover of Time asks: “Can Anyone Stop Hillary?”

As usual where Clinton is concerned, there is controversy and ambiguity. The magazine’s choice of images was a disembodied leg in a pantsuit, and a tiny emasculated figure hanging from the tip of her sensible pump.

One thing is clear: At 66, the possibilities ahead for Hillary Clinton look far greater than anyone would have guessed 16 years ago, all the way back when she was turning 50.