SAN FRANCISCO — Golden “50s” cover this city. They glow from the waterfront’s Ferry Building, hang from streetlights and cover 20 stories on downtown skyscrapers — all promoting the weeklong party that is the 50th Super Bowl, to be played on Sunday.

But these festive trappings cannot mask the tensions that have roiled San Francisco in recent years — tensions that are coming to the surface as football fans flood into town and attend over-the-top pregame events. In a city divided over gentrification, sky-high housing prices and the technology industry’s influence on local government, even the nation’s biggest party has become a battleground.

The cost of hosting the Super Bowl — estimated at about $5 million for the city — has unleashed a storm of anger among residents already resentful of the influx of expensive restaurants, high-end stores and rich, young tech workers who have snapped up apartments in historically low-income neighborhoods. To tidy up for the tourists, the city’s large homeless population has been swept out of view, which some people here see as evidence that this city, long a seat of leftist activism, has sold itself to corporate interests.

“I don’t think the taxpayers should be used to subsidize a party for one of the wealthiest corporations in the world,” said Jane Kim, a San Francisco supervisor. Last week, she introduced legislation to renegotiate the city’s agreement to host the National Football League, noting that Santa Clara, the Silicon Valley city 40 miles to the south of here where the game itself will be played, will be largely reimbursed for its costs by the Super Bowl Host Committee.