Her bill, reintroduced in March and co-sponsored by another presidential candidate, Kirsten Gillibrand, includes a hefty infusion of money to nonprofit developers of affordable housing, paid for by raising the estate tax. A Moody’s analysis projected that the added resources, about $50 billion a year, would help build enough new housing to push rents a decade from now about 10 percent lower than they would be without Ms. Warren’s bill. That estimate, however, treats the nation’s supply of housing as a single market, and the real effects would most likely be different in Boston and in Des Moines.

Ms. Warren’s bill also includes down payment assistance to new homeowners living in neighborhoods that were historically redlined by banks, in an effort to narrow the black-white homeownership gap. She and Mr. Booker also want to nudge local communities to allow more housing by changing zoning laws that block the construction of apartments or denser housing. Such laws have the effect of maintaining economic and racial segregation, and analysts on the left and right view them as a key driver of high housing costs.

Ms. Warren wants to dangle a new pot of federal money to communities that change such laws. Mr. Booker’s bill would punish those that won’t, by withholding community development grants. Either proposal would mean more federal intervention in decisions long viewed as inherently local. But both Ms. Warren and Mr. Booker argue that federal policies helped shape local communities more than residents often acknowledge.

“My whole life experience has been seeing how federal laws that were bigoted and biased created disinvestment in certain communities and created wealth and opportunity in others,” Mr. Booker said. “Federal policy literally helped to design cities as we know them.”

It follows, he said, that the federal government should help change those patterns.

That’s an argument that Mrs. Clinton sidestepped just three years ago, even as her economic agenda included a proposal to increase federal spending on housing. In reality, the Democratic coalition also includes many homeowners who don’t want new rental housing nearby — or who benefit from the tight housing supply that has driven up the value of their homes.

The Moody’s analysis that Ms. Warren often cites also concludes that her bill would slow the appreciation of home prices. But in the early stages of courting renters, these candidates are not yet talking about how helping them may require concessions from more than just the people rich enough to pay estate taxes.

“That’s a huge problem for the whole zoning reform debate — there’s just no way to slice it that a vast number of wealthy, powerful people aren’t going to have to make some significant sacrifice,” said Kenneth Stahl, a law professor at Chapman University. “Candidates have to think about whether they’re going to be rewarded for going out on that limb.”