captioning sponsored by macneil/lehrer productions woodruff: rebels in syria said today they would not stop fighting until president bashar al-assad is gone. good evening, i m judy woodruff. brown: and i m jeffrey brown. on the newshour tonight: two years into the syrian uprising, we look at the situation on the ground, and the diplomatic debate over aiding the rebels. woodruff: kwame holman reports from the annual gathering of american conservative activists, who are trying tchartheir political future. with last november s defeat of mitt romney, this key bloc of conservative enthusiasts has set its sights on a new goal: reshaping and re-energizing the republican party. brown: mark shields and david brooks analyze the week s news. woodruff: miles o brien continues his investigation into drinking water contaminated with chromium six and the regulators responsible for cleaning it up. yeah, it causes cancer. that s the biggest health concern. we know that for