If the critique of Hillary Clinton from the left is that she isn’t progressive enough, consider her approach to paying for family leave.

Clinton returned to the campaign trial in North Carolina on Sept. 15, and while most of the coverage focused on her health, she also used the appearance to trumpet her plan to provide 12-weeks of paid time off for new parents or to recover from illness. Her proposal, which also covers people caring for family members, would ensure anyone taking advantage of the Family Medical Leave Act would receive at least two-thirds of their wages. Currently, the FMLA, signed into law by president Bill Clinton in 1993, only requires that employers give unpaid time off.

While most other nations mandate paid leave after childbirth and for other medical issues, the US remains an outlier (Papua New Guinea is the only other nation that offers no paid maternity leave). Some US employers offer it to their employees—and in highly competitive fields like consulting and tech, there’s an arms race to offer the most generous policies—but only 12% of US private sector workers are covered by employer policies, according to the Department of Labor.

In its provisions, Clinton’s plan is similar to the Family Act, which was introduced in Congress in 2013 by Sen. Kirsten Gillibrand and Rep. Rose DeLauro, Democrats from New York and Connecticut, respectively. Where they differ is in who pays. The Family Act, which is based on similar state programs in New Jersey and California, calls for a modest tax on employers and workers, totaling 0.2% of annual pay, paid into a Social Security-type trust fund. Clinton’s plan, by contrast, proposes taxing the wealthy to pay for it.

Clinton’s plan is vague— she doesn’t specify who will be taxed, or by how much — and it puts her to the left of her former socialist rival Bernie Sanders, as well as most Congressional democrats, who back the Family Act. While her website criticizes other proposals “for increasing taxes on working families,” her campaign is more gracious about the rival Family Act. In an email to Quartz, Clinton spokeswoman Rebecca Chalif wrote:

Hillary applauds efforts to put actual paid family and sick leave policies front and center, like the Family Act championed by Senator Gillibrand and Representative DeLauro. While Hillary will fight for the central guarantees of the Family Act, she has a different way of paying for the proposal. Her paid-leave plan meets the scope of America’s urgent need for paid family and sick leave by asking the wealthiest Americans to pay their fair share.

Neither plan is guaranteed passage, particularly if Republicans hold on to Congress after the upcoming election, and the business lobby is likely to fight either proposal. But supporters of the Family Act have been diligently building support with employers, and companies ranging from Morgan Stanley to SAP say they support it. Because it puts some of the burden of paying on workers, it’s likely more palatable politically than a new tax bracket for the wealthy.

Donald Trump’s plan, which he fleshed out this week, would provide six-weeks of paid maternity leave for new mothers through an expansion of unemployment insurance, paid for by finding new efficiencies in the insurance program.

The National Partnership for Women & Families, a nonprofit which has spent decades fighting for paid leave, said the funding mechanism is not critical. “The core thing is the policy gets enacted, and gets enacted quickly,” says Vicki Shabo, the organization’s vice president. But she noted that if the program is funded from general revenue, as Clinton proposes, it could be subject to means-testing and potentially all but the very poor could be excluded.

Why is Clinton proposing a plan with a harder path to passage? One theory, offered by Bryce Covert at Slate, is that because she pledged not to raise taxes on anyone earning less than $250,000, she’s can’t endorse a payroll tax that applies universally. Or she may be staking out an extreme position as a negotiating tactic.

Whatever her reasons, family leave has now become an issue for both campaigns. That should give hope to would-be parents who can’t afford the time off to have children, and may finally separate the US from New Guinea.