President Trump’s support of a tentative deal to avert another shutdown was in doubt Tuesday morning, rekindling concerns that continual government dysfunction could inflict long-term damage to a massive government program that millions of low-income Americans rely on for housing.

In an era of divided government, with each side unwilling to compromise and shutdowns increasingly common, experts, landlords and housing advocates are wondering how the Section 8 housing voucher program — which requires certainty and stability — can thrive in a political environment that provides neither.

Every shutdown, according to experts and landlords, erodes faith landlords have that the government will pay its share of subsidized tenants’ rent, an outcome once considered inconceivable, but one that just came within weeks of reality. That uncertainty could make it less likely landlords will decide to rent to housing voucher recipients — the only way the program functions — exacerbating a housing crisis already unfolding in cities across the country.

Now, with another shutdown looming on the heels of a record 35-day closure, experts and landlords are expressing concern about the long-term consequences for a program that was created in 1974 as a way to move some people out of concentrated pockets of poverty in public housing developments and that today supports 2.4 million people.

“The government shutdown has clearly given landlords additional pause,” said Tom Bannon, the chief executive officer of the California Apartment Association, which represents 900,000 rental units throughout the state. “It makes the program even less attractive.”

The additional strain comes at a time when the program is already besieged by numerous pressures that have left many landlords hesitant about participating.

A booming housing market, particularly in gentrifying and gentrified cities, has driven up the costs of renting, convincing some landlords more money can be made on the private market. Then there’re bureaucratic hoops that landlords have to undertake, including frequent housing inspections and greater oversight.

Finally there’s the fact that voucher recipients, poor and disproportionately African American and Latino, are “highly stigmatized” and perceived as less attractive tenants, said Eva Rosen, an assistant professor with Georgetown University who has extensively studied why landlords participate in the program.

All this has made numerous cities unwelcoming to recipients of housing vouchers, according to a sweeping report released last year by the Urban Institute, whose findings challenged the premise that beneficiaries can move wherever there’s affordable housing.

The reality: An “extremely difficult” search rife with rejections, long waits and dead ends. The researchers sifted through 341,000 rental advertisements and found only 8,735 units that were available and charged monthly payments within the local voucher rent limits — a rate of less than 3 percent.

The rates of acceptance among landlords vary widely from city to city. In the District, where local law prohibits disqualifying voucher recipients, only 15 percent of landlords automatically reject voucher recipients. Some municipalities, like San Jose and Baltimore, have recently considered legislation that would offer the same protections.

Meanwhile, in Fort Worth and Los Angeles, more than three out of four landlords disqualify voucher beneficiaries, the report said.

“They don’t think they can count on the program, or have issues with the program,” said Mary Cunningham, one of the authors of the Urban Institute report. “Already landlords were thinking about this issue — prior to the government shutdown.”

Rosen, the Georgetown professor, last summer authored a study in Housing Policy Debate that drew on interviews with 127 landlords in Baltimore, Dallas and Cleveland. It found that the majority of landlords that decline to rent to recipients of housing vouchers had previously gone through bad experiences participating in the program — like becoming disillusioned with the local housing authority — and had soured on it.

The No. 1 reason that landlords remained in the program, the study said, was its sense of stability. The government simply seemed like a better bet than a random tenant. This was especially true in Baltimore, home to many mom-and-pop landlords who depend on timely payments to tend to their own bills and mortgages. For them, a few missed payments can be the difference between profit and insolvency.

“When you talk about certainty and stability, it’s financial stability, it’s knowing that they wont have to worry about paying their mortgages,” Rosen said.

For many landlords, that has historically been worth the headaches of renting to housing voucher recipients — but experts worry that commitment could soon fray.

Shutdowns “will have harmful long-term effects on these programs,” said Doug Rice, a senior policy analyst with the Center on Budget and Policy Priorities. “It removes the selling point in this program. ... The long-term corrosive effects are undeniable.”