America can't afford to have Ben Carson continue as head of the Department of  Housing and Urban Development; least of all Philadelphia, whose shortage of affordable housing is intolerable.

Carson is yet another Trump appointee whose main job is to undermine the very Cabinet department he was selected by the president  to lead.

Since his appointment last year, Carson has proposed tripling rents paid by the poorest families in government-subsidized housing and suspended an Obama administration rule imposed to improve enforcement of the 1968 Fair Housing Act.

Carson is the wrong person to be in charge of HUD, especially when Philadelphia is starving for more affordable housing units. A review by the Federal Reserve Bank of Philadelphia showed the city actually lost 23,628 units with rents below $750 a month between 2000 and 2014.

"The shrinking number of low-cost housing in Philadelphia leaves lower-income renters saddled with higher rent burdens, greater financial stress, and insecure housing arrangements," said the Fed report. "At the community level, the loss of affordable units contributes to residents being segregated by income and socioeconomic status."

The report said the loss of affordable housing is most acute in gentrifying neighborhoods like University City and Graduate Hospital, where the loss of low-cost units is occurring at more than five times the rate in nongentrifying neighborhoods.

That assessment shows it is largely a myth that gentrification leads to greater diversity, given that those least likely to afford high rents are typically poor African Americans and Latinos.

Philadelphia isn't alone. HUD's own Worst Case Housing Needs report says severe housing problems nationally have grown 41 percent since the Great Recession. "Modest gains in household income were met with rising rents, shrinking the supply of affordable rental housing stock," said the HUD report.

Yet HUD's leader seems on a mission to make it even harder for lower-income families to find a place to live. Carson wants to raise the rent for subsidized housing from 30 percent to 35 percent of a family's gross income, which would affect 4.7 million households, and raise the cap on rent charged to the poorest families from $50 a month to $150 monthly, which would affect 712,000 households.

He also wants to stop allowing deductions for medical and child care costs when calculating rent, saying, "We really want to level the playing field and make it much even for everyone."

HUD was created to give poorer families with housing needs an advocate in the president's Cabinet. Carson instead prefers to play the role of an unsympathetic enforcer. The changes he would make will hurt people, not help them. And this comes from a man who until a ruckus was raised thought nothing of buying a $31,000 furniture set for his office suite.

Carson is doing the president's bidding, so he has little to fear from the Oval Office. But if he has a shred of the moral fiber that led him to become a physician, a healer, Carson would admit he isn't the right person to carry out HUD's core mission and step aside.