InsideClimate: Arkansas state legislators leery of lax federal oversight of oil pipelines have attempted to beef up safety standards to try to prevent another disastrous spill in their own backyard. They're aware, however, that their efforts are largely symbolic. That's because, in most instances, a state statute cannot infringe on the federal government's constitutional authority to set and enforce rules about petroleum pipelines. But for local lawmakers trying to calm constituent fears after a 65-year-old pipeline...