Even before formally joining the presidential race, Elizabeth Warren made it clear what kind of candidate she wanted to be: a populist crusader who doubled as a check on the power of corporations and the super-rich. Not long after announcing her candidacy, she proposed a "wealth tax," a 2 percent tax on families with assets over $50 million and 3 percent on those with assets over $1 billion. It would generate an estimated $2.75 trillion over the next ten years, and now we know what Warren wants to do with that money: fund a national child-care program.

In a post on Medium published Tuesday, Warren writes, "In the wealthiest country on the planet, access to affordable and high-quality child care and early education should be a right, not a privilege reserved for the rich." Earlier this year, a New York Times poll found that 64 percent of young-adult respondents were putting off having kids because of the high cost of child care. In Massachusetts, Warren's home state, the average annual cost of child care for an infant is $17,062. Even in a less expensive place like Iowa, the average annual cost is $9,485, nearly two-thirds of full-time income at state minimum wage. That means a single parent at a minimum-wage job has to work eight months of the year just to cover that.

In her Medium post, Warren lays out the main points for her plan:

The federal government will partner with local providers — states, cities, school districts, nonprofits, tribes, faith-based organizations — to create a network of child care options that would be available to every family.

These options would include locally-licensed child care centers, preschool centers, and in-home child care options.

Local communities would be in charge, but providers would be held to high national standards to make sure that no matter where you live, your child will have access to quality care and early learning.

Child care and preschool workers will be doing the educational work that teachers do, so they will be paid like comparable public school teachers.

She goes on to say that the level of proposed federal funding would allow local providers to offer these services completely free to families making less than 200 percent of the federal poverty line (which can be as low as $17,000 for a family of two), and capped at 7 percent of income for any family over that threshold. And Warren estimates the cost of her program at $700 billion over 10 years, well below the $2.75 trillion her wealth tax would generate. (It's also worth noting that as a tax on total assets, this is distinct from the marginal income tax that incensed Howard Schultz enough to run for president himself.)

By current estimates, 15 million kids, or 21 percent of all U.S. children, live in poverty, and despite frequent demonization of the poor, most of those children are in families with working parents. By contrast, Warren's proposed tax would affect 75,000 families who collectively control more wealth than the rest of the country combined. Unfortunately, those families have much greater sway in D.C. than the rest of the country does, and more centrist candidates might find it more advantageous to fight Warren than to back her calls for relatively modest tax increases.