National At the ever-growing bottom of the American economy, a low-wage worker becomes a minimum-wage activist At the ever-growing bottom of the American economy, a low-wage worker becomes a minimum-wage activist Sara Fearrington offers coffee to a 6:30 a.m. customer at Waffle House in Durham, N.C. She struggles to support her family on tips. (Photos by Michael S. WIlliamson/The Washington Post) By DURHAM, N.C. — She had been riding the city bus almost every day for the past decade without paying much attention to the people around her. Sara Fearrington, 43, was usually isolated in the fog...…National At the ever-growing bottom of the American economy, a low-wage worker becomes a minimum-wage activist At the ever-growing bottom of the American economy, a low-wage worker becomes a minimum-wage activist Sara Fearrington offers coffee to a 6:30 a.m. customer at Waffle House in Durham, N.C. She struggles to support her family on tips. (Photos by Michael S. WIlliamson/The Washington Post) By DURHAM, N.C. — She had been riding the city bus almost every day for the past decade without paying much attention to the people around her. Sara Fearrington, 43, was usually isolated in the fog...WW…