Ben Carson, the secretary of Housing and Urban Development (HUD), wants to pare back Obama-era housing regulations that he says do not do enough to address the real driver of housing costs: zoning regulations.

On Monday, Carson announced that he was looking to revise the 2015 Affirmatively Furthering Fair Housing (AFFH) rule, which sought to combat housing segregation by requiring local governments to perform extensive (and expensive) reviews on how concentrated their neighborhoods were along class and racial lines, and then to develop action plans to create more "balanced and integrated living patterns." Local governments that failed to fulfill either requirement would be cut off from a number of federal housing grant programs.

Carson said on Monday that he wants to replace the 2015 AFFH with new rules that focus on increasing the overall supply of housing.

"I want to encourage the development of mixed-income multifamily dwellings all over the place," Carson told The Wall Street Journal, saying, "I would incentivize people who really would like to get a nice juicy government grant" to reform their zoning codes.

According to the Journal, Carson specifically called out Los Angeles for its strict single-family zoning rules that limit the number of housing units that can be built in the city. "Of course you're going to have skyrocketing prices that no one can afford," he said.

That Carson would want to reform the AFFH rule is not terribly surprising, given that he has been a critic of it long before he was appointed HUD secretary. As far back as 2015, Carson criticized the AFFH rule as an example of "social engineering" and "failed socialism." As HUD secretary, he has already taken steps to weaken it, such as pushing back compliance deadlines for local governments until 2020.

What is surprising, however, is Carson's suggestion that the AFFH be retooled to tie HUD grants to localities loosening their zoning regulations.

This is a complete 180 from Carson's 2015 criticism of the AFFH rule, in which the then-presidential candidate fretted that the Obama administration's focus on housing desegregation would do too much to undo local zoning laws.

"The [AFFH] rule would fundamentally change the nature of some communities from primarily single-family to largely apartment-based areas by encouraging municipalities to strike down housing ordinances that have no overtly (or even intended) discriminatory purpose—including race-neutral zoning restrictions on lot sizes and limits on multi-unit dwellings," wrote Carson in a 2015 Washington Times op-ed.

Carson's change of heart has raised eyebrows and even caused some commenters to question the sincerity of his new talk about tackling restrictive zoning rules.

Nevertheless, the shift in thinking at HUD—even if it is just a rhetorical shift at the moment—is still cause for cautious optimism, says Vanessa Brown Calder, a housing policy expert at the Cato Institute.

"I do think that shift in attitude at HUD is huge, and I hope that it translates into educating local municipalities that these things are related, zoning restrictions and housing affordability," says Calder. "It does sound like there is going to be some attempt made to connect HUD subsidies to relaxing or reforming zoning regulations, so that I think that could be really important."

That this might come in conjunction with a paring back of the Obama-era AFFH rule is heartening as well, says Calder, given both the costs and shaky legal foundations of the 2015 regulation.

The original AFFH, she notes, cost cities some $55 million in compliance costs. Indeed, these costs were burdensome enough that many localities decided it would be cheaper to just not comply with the rule and forfeit HUD funding.

The legal basis for the 2015 AFFH rule—which is based on the 1968 Fair Housing Act—is also pretty thin, says Calder. The 1968 law, she notes, is focused on eliminating racial discrimination by landlords, not on creating a delicate racial and income balance across whole cities, as is called for in the Obama administration's 2015 rule

"Zero times in the Fair Housing Act do they talk about segregation. That seems kind of damning considering that's what [the AFFH rule] is all about," Calder tells Reason.

Carson has so far avoided calling for an end to the AFFH rule altogether, instead suggesting that it be revised so as to reduce the overall regulatory burden on local governments. That approach is in line with many of the Trump administration's other deregulatory actions, which emphasize reducing and streamlining federal regulatory burdens, rather than eliminating rules in their entirety.

Nevertheless, any reduction in the regulatory state is welcome, as is anything that draws attention to restrictive zoning laws that have reduced supply and raised prices in cities across America.