Imagine a late-night television commercial aimed at Washington’s wonks: Tired of your same old tax credits and grant proposals? Ever dreamed of a policy tool that improved children’s health, bolstered income and eradicated poverty — all without costing the government a penny? Then, a smash cut to a wedding scene.

With Democrats and Republicans pitted against one another in a vicious election-year battle over how to alleviate poverty, marriage is the policy solution du jour. Take a speech given by Senator Marco Rubio last month on the 50th anniversary of the War on Poverty, Lyndon B. Johnson’s governmental campaign to boost the opportunity and incomes of the poor. When it started, “93 percent of children born in the United States were born to married parents. By 2010 that number had plummeted to 60 percent,” Rubio said, calling marriage “the greatest tool to lift children and families from poverty.”

Rubio did not just pull the notion out of thin air — or, for that matter, Corinthians. Economists have done studies showing that if you snapped your fingers and suddenly all the country’s poor, unmarried partners were hitched — including gay and lesbian couples legally precluded from marrying in most states — the poverty rate would drop. With social trends pushing partners apart, why shouldn’t the government push them together — and help end poverty and improve the lot of children while we’re at it? It’s a rare policy solution that data-crunching geeks and Bible-thumping crusaders can agree on — albeit for very different reasons. Unfortunately, there might not be much that Washington can actually do about it.

Nobody doubts that where marriage is, poverty tends not to be; the statistics are stark. Almost no marriages in which both partners work full time fall below the poverty line; about one-third of households headed by a single mother are poor. One in eight children with two married parents lives below the poverty line; five in 10 living with a single mother do. And income aside, children raised by two parents are less likely to have behavioral problems, be asthmatic or hungry; they are more likely to achieve at school and so on. The effects are perhaps even larger than researchers had previously grasped. In a new study, the economist Raj Chetty and his co-authors found that, in terms of income mobility, nothing matters more for a low-income child than the family structures she sees in her community — not neighborhood segregation, school quality or a host of other factors.