SAN FRANCISCO (KGO) -- The most significant case on homelessness in more than 40 years goes before the U.S. Supreme Court on Monday.
Arguments center around whether unhoused people can be punished for sleeping outdoors, when they have no other options.
Advocates for the unhoused rallied to bring attention to this in San Francisco on Monday morning.
RELATED: How could the US Supreme Court's case Grants Pass v. Johnson impact SF unhoused community?
Dozens of advocates marched from the Federal Building off of Golden Gate Avenue to the State Building and then to San Francisco City Hall.
It's a crisis in many Bay Area cities with thousands of unhoused citizens, sleeping on the streets or in encampments. And soon, cities may have more authority over where they can stay.
MORE: Supreme Court case on homelessness could have implications for Bay Area cities, experts say
The majority of the Supreme Court appears inclined to rule in favor of Grants Pass Oregon, allowing the city to punish unhoused people for sleeping or camping in public spaces.
It's a ruling that could have major implications across the Bay Area, including San Francisco, which is in the middle of its own court battle centering on encampment sweeps.
RELATED: Supreme Court to review homelessness case that's been preventing encampment sweeps
The Western Regional Advocacy Project, which is a collection of homeless coalition, hosting a protest Monday morning, says this ruling would create a devastating ripple effect for homeless people across our region.
"You can't just criminalize somebody who doesn't have any place to live, to sleep, legally indoors. You can't criminalize them for sleeping outside when they have no alternative. People are going to sleep," Paul Boden, Director of the Western Regional Advocacy Project said.
"Housing, nothing ends homeless like a home, it's about time we woke up and realize that it may be a very simple statement but it's also very true," he said.
MORE: These Bay Area cities, counties received CA homeless encampment cleanup grant funding
Governor Gavin Newsom already submitted a brief last month, in support of overturning Grants Pass.
His office says this ruling has found state elected officials embroiled in years-long lawsuits, blocking even the most common-sense efforts to clear encampments posing health and safety concerns.
MORE: LA homeless man builds makeshift home next to freeway: 'It's in good condition'
"California is investing billions to build housing and provide the services needed to get people out of tents and into safer situations," Newsom said. "However, our best efforts are being blocked because of sweeping injunctions that delay progress and fail to provide any consistent guidance for local authorities to abide by."
The Supreme Court is expected to make a ruling on this by the end of June.
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