Supporters of the Affordable Care Act celebrate outside the Supreme Court in 2012, after a divided court upheld the law as constitutional by a 5-to-4 vote. The latest battle, which the Supreme Court hears Wednesday, is over whether people who buy insurance through federally run exchanges are eligible for subsidies. David Goldman/AP hide caption

itoggle caption David Goldman/AP

Abortion-rights opponent Brian Normile of Beavercreek, Ohio, holds up a poster during a prayer vigil outside Planned Parenthood in Washington, D.C., in January. Alex Wong/Getty Images hide caption

itoggle caption Alex Wong/Getty Images

Uzuri Pease-Greene, right, leads a walk through the public housing complex in the Potrero Hill neighborhood of San Francisco where her family lives. She is working to have the old buildings replaced. Talia Herman for NPR hide caption

itoggle caption Talia Herman for NPR

Freedom House paramedics, who first were deployed in the 1960s, provided a crucial service for Pittsburgh residents. The program became a national model for emergency medical transport and care. Courtesy of University of Pittsburgh hide caption

itoggle caption Courtesy of University of Pittsburgh

Chris Newman, seen at her home in Los Molinos, Calif., calls the change she helped get made to lung cancer treatment guidelines a "small, but very important victory." Courtesy of Chris Newman hide caption

itoggle caption Courtesy of Chris Newman