“Appetite for these policies only continues to grow, so as the federal government continues to drag its feet, more and more states and cities are stepping up,” said Aparna Mathur, a resident scholar at American Enterprise Institute, a right-leaning think tank.

The policies acknowledge that 71 percent of women with children under 18 are in the labor force, and both parents work in 61 percent of married families with children, according to the Bureau of Labor Statistics. There is widespread support among voters for policies that help make those two roles possible. It’s particularly important for low-income women, advocates say, because they are more likely to quit the labor force altogether after the birth of a child or after a family illness if they don’t have benefits like paid leave.

The new policies have passed mostly in blue states. Republicans have traditionally opposed them as being onerous for business or expensive for government. But recently, there have been more bipartisan efforts. A Republican state senator, Joe Fain, was the primary sponsor of Washington’s paid leave bill, with Democratic co-sponsors. On Saturday, a law went into effect in Georgia, a red state, allowing workers to use their personal sick days to care for immediate family members.

The Trump administration included a paid leave plan in its budget proposal, the first from a Republican administration. But many advocates say it is insufficient because it would cover only new parents, for a maximum of six weeks and with an uncertain financing source.

States and cities have long been incubators for new policy ideas, particularly those supported by the party not in power at the federal level. The economic effects of various experiments can be assessed on a smaller scale. Opponents sometimes respond by passing state-level pre-emption laws that prohibit cities from passing laws on certain issues. But the strategy is being used more because policy making in Congress is moving so slowly, experts say.