In the late 1980s, Brian Flagg began a new Christmas tradition that lasted for 14 years. He camped out with homeless protesters at the Tucson (Ariz.) Federal Building. Complementing the nativity scene on display there, the protesters posted a sign that read “Still no room at the inn.

Flagg, who has directed Tucson’s Casa Maria homeless center for the past 22 years, was taking part in a historical trend: the steady increase in the number of homeless protests over the course of the 1980s. Sociologists David A. Snow, Sarah A. Soule, and Daniel M. Cress explore how cities’ economic, political, and demographic features fed this trend in a March 2005 Social Forces article. They conclude that not just duress (more poverty and unaffordable housing) but also largesse (higher per capita income and transfer payments) pushed more and more homeless people to take to the streets in the 17 large American cities they studied. The authors also found that cities’ political climates were not related to the rise of homeless protests, although they emphasize that political climate plays a role in the emergence of other types of social movements.

“People often think that activists are propelled by strident grievances alone. Snow says. “But you need resources to mobilize protest, especially when you’re mobilizing people like the homeless who are economically deficient. As the wealth of a city [such as its per capita income] increases, so does the likelihood that some portion of that wealth will be channeled through organizations to activists who advocate for marginalized people.

One such channeling organization is Casa Maria. As part of the Catholic Worker Movement, Casa Maria operates according to the motto “Comfort the afflicted and afflict the comfortable. Flagg divides his time accordingly, spending his mornings serving coffee, soup, and sack lunches to about 850 people, and his afternoons and evenings organizing homeless people and garnering public support for social justice. The organization’s downtown Tucson headquarters also provides showers, clothes, mail service, legal services, and phones to its clients.

Casa Maria exists on private donations, all of which are entered into one coffer to be used for both charity and activism. “For the entire history of the Catholic Worker Movement, which was founded in 1933, says Flagg, “people have said, ‘I love it when you serve food, but I hate it when you do social justice work,’ – although the words they use often aren’t that nice. But charity and justice are two sides of one coin. Whatever resources we have go toward both sides of that coin. This is our tradition, and it’s totally in line with the Gospel. We’re on the rooftops screaming that.

Casa Maria’s screaming – as well as its distribution of food, space, modes of communication, and office supplies – was essential to the mobilization of homeless people in Tucson in the ’80s, says Snow. And backing Casa Maria were private donors. “Sometimes we have a minimalist view of activism – you’re not an activist unless you take to the streets, he says. “But benevolent funding is also an important part of activism.

Read more stories by Alana Conner Snibbe.