1/ Over the last few months, Trump has tried to rile up white suburbanites by speaking out against #AFFH (affirmatively furthering fair housing), a requirement first included in the 1968 Fair Housing Act (aka Title VIII of the Civil Rights Act.)
2/He has pledged to protect the "Suburban Lifestyle Dream," namely keeping affordable housing out of the suburbs by forbidding the implementation of AFFH. 
3/In 2015, the Obama admin. issued an AFFH rule requiring municipalities receiving HUD funds to report barriers to fair housing and to develop plans to expand housing opportunity. However new these rules appeared, they were basically version 2.0 of past HUD fair housing rules.
4/AFFH, however, has never been implemented or seriously enforced. Since the 1970s, efforts to open up housing opportunities in exclusive suburbs have faced serious obstacles.
5/Many white-majority suburban municipalities are exquisitely sensitive to NIMBY politics and have long used everything from environmental impact and traffic studies to zoning regulations to keep affordable housing out.
6/Real estate brokers have been crucial players in creating and maintaining racial discrimination through such practices as steering (directing whites but not Blacks, Latinos, et al. to predominantly white neighborhoods and vice versa).
7/The real estate industry is also one of the most important players in local politics throughout the US. In low turnout races, a little funding from brokers and developers can go a long way. Often local officials are the tools of brokers and developers.
8/It's very hard, given these constraints--and politicians' willingness to stoke and respond to their constituents' fears--to expand housing markets in exclusive communities.
9/The federal government, despite Trump's shouting, does not have the power to do much to intervene in local housing matters--and the AFFH rules (before Trump revoked them) didn't give regulators a lot of teeth.
10/HUD has the power to investigate discrimination claims and take action against property owners, realtors, and landlords who violate fair housing law. HUD is often aided by state or local fair housing nonprofits that take complaints and gather information.
11/The DOJ can step in when they find evidence of "pattern and practice" discrimination as they did with the Trump Management Co. back in the 1970s. (The FBI released material from its investigations available here: vault.fbi.gov/trump-manageme…)
12/Litigation is, however, time consuming and costly. As a result, it's not the most effective way to promote fair housing. And when it comes to local governments fighting efforts to build affordable housing, cases can get tangled up in litigation for years.
13/ And even when the federal government prevails in battles to desegregate housing in predominately white places like Westchester County, NY, county and town governments have all sorts of ways of stalling or thwarting affordable housing development. nytimes.com/2009/08/11/nyr…
14/ The result is precious little affordable housing has gone up in Westchester. antibiaslaw.com/article/court-…
15/The Obama administration's #AFFH rules, basically shelved by Trump's HUD well before this month's presidential twitterstorm, were never going to solve the problem of separate, unequal housing, housing unaffordability (especially in suburbia), and persistent discrimination.
16/What we are seeing with Trump's attacks on #AFFH is an effort to rile up his base by appealing to their racial fears. As with so many of Trump's culture wars blasts, this one is not reality based because AFFH has simply not remade suburban housing markets.
