A coalition of state and local leaders gathered in North Park on Tuesday to show their support for Proposition One, a bond initiative that could raise $4 billion for affordable housing. Senate President Pro Tem Toni Atkins, D-San Diego, noted the broad coalition of supporters at the news conference, which was attended by representatives from businesses, labor, the health industry and nonprofits. “One in three Californians can’t afford their rent,” she said outside the San Diego Housing Federation offices on Iowa Street. “That’s why we’re here. It has become a humanitarian crisis. And we are a great state, and we are better than that.” Proposition One, the Veterans and Affordable Housing Act, is on the November ballot and would generate $4 billion for affordable housing, with $1 billion specifically for veterans.