A supporter holds a sign promoting a movement to raise the minimum wage in San Diego and guarantee paid sick days for workers in 2014. (Mike Blake/Reuters)

PEOPLE SHOULD be able to take medical leave, particularly during and after pregnancies, without worrying about getting fired or going broke. This is both a humane goal and, given that it promotes healthy childbearing and stable families, an investment in the nation’s future.

Federal law in this area falls short. The 1993 Family and Medical Leave Act requires employers to offer 12 weeks of unpaid leave, but the law covers only about 60 percent of workers, according to the Council of Economic Advisers . Moreover, for those whose employers don't offer paid leave, taking time off may be unaffordable.

Unsurprisingly, the Council of Economic Advisers found that low-income and minority groups have the least access to paid leave options. For every five workers who reported taking family or medical leave in 2011, one reported not being able to take needed time off. For low-income workers, the primary challenge was financial; better-off workers cited "too much work," not financial difficulties, as the principal barrier.

With this picture in mind, thoughtful policy would set two goals. First, the government should reduce financial obstacles for the poor and middle class. Instead of mandating that employers offer paid leave — which, among other things, doesn’t help contractors or the self-employed — the government should provide progressively scaled payments to those who would face real financial strains in taking leave. Second, the government should more deeply entrench requirements that workers can’t be penalized for taking leave, whatever their income. That would involve expanding the Family and Medical Leave Act’s existing protections.

Instead of this sort of plan, however, the one that's getting the most attention is from presidential candidate Sen. Bernie Sanders (I-Vt.) and a slew of Senate Democrats. Mr. Sanders, who seems never to miss an opportunity to propose creating a universal entitlement where one isn't necessary, favors a paid leave benefit available to all workers, regardless of income. Instead of progressively scaling down with income, benefits actually increase with income, to a maximum of $4,000 per month. Everyone, even millionaires, could claim benefit checks. Meanwhile, everyone's Social Security taxes, even non-millionaires', would go up to pay for it. Progressives should be very uncomfortable taxing all wage earners in part to finance benefits for the wealthy.

The idea is of a piece with Mr. Sanders's broader agenda to massively expand universal entitlements just as the universal programs already in place are set to crowd out all other spending in the federal budget. He piggybacks on the popularity of programs such as Social Security and Medicare, when those are hardly the only models available to policymakers seeking to improve the social safety net. Indeed, they cannot be the models policymakers choose in an era in which carefully husbanding national wealth is increasingly crucial.

Read more on this issue:

The Post’s View: D.C.’s paid-leave proposal goes way too far

Katrina vanden Heuvel: Behind the momentum for paid sick leave

The Post’s View: Bernie Sanders isn’t as progressive as you think