But there seems to be broad support for paid leave in the United States. A bipartisan poll conducted on behalf of the National Partnership for Women and Families, a pro-leave group, just after the 2012 election, found that 86 percent of Americans supported leave—including 96 percent of Democrats and 73 percent of Republicans. The poll inspired new hope that President Obama might take up leave in his second term.

Instead—vindicating Clinton’s opinion that leave is politically impossible right now—the issue has all but disappeared, overtaken by gridlock, government shutdown, and controversies over Obamacare and foreign policy.

Late last year, Senator Kirsten Gillibrand of New York and Representative Rose DeLauro of Connecticut, both Democrats, introduced the Family and Medical Insurance Leave Act, which proposed offering new parents and caretakers the ability to take 12 paid weeks off each year. Workers would contribute 0.2 percent of their wages to the Social Security Administration, which would handle paying bills. Employees could only get up to 66 percent of their monthly income, but that's a great deal more than the 0 percent workers in 47 states currently receive if they stay home with a loved one.

But the bill is stalled in the House. The last action it saw was on December 12, 2013, when it was referred to committee, where it disappeared and has yet to be brought up again. It received broad support from Democrats—87 of them, to be exact—but not a single Republican; GOP politicians argue the bill would hurt small businesses. The president's 2015 budget includes a plan for a $5 million "State Paid Leave Fund," but he hasn't made it a priority.

Why is paid family leave so controversial?

First, it's pricey. The three states that have paid family leave fund their individual programs through employee-paid payroll taxes, then manage the disbursement of funds through disability programs. In plain English that means increasing taxes and hiring more government administrative staff. Meanwhile, small businesses complain that the paperwork and time needed to provide paid time off is a major burden, which is why the 1993 law only requires companies with 50 or more employees to offer leave.

A 2009 piece in Newsweek even suggested employers might be less willing to hire women if paid-family-leave laws were in place:

Mandated paid family leave makes it more expensive to hire workers, particularly women. That makes employers less willing to hire women, especially those with limited education or skills who typically do the kind of work it's easy to find someone else to do. If the objective is to help poor women remain employed, mandated paid family leave will do exactly the opposite.

That’s an especially important question since single mothers, who arguably need paid leave most, tend to be poorer.