Hillary Clinton pledged to make combating climate change a central focus of the 2016 presidential campaign, saying Monday that she would not allow “deniers” to thwart progress or prevent the U.S. from leading on the issue. While Mrs. Clinton cast herself as a crusader for clean energy, she declined to weigh in on a key environmental debate, taking no position on whether to build the Keystone XL pipeline. At an event in Iowa touting her climate plan, Mrs. Clinton said that as secretary of state, she set in motion the review evaluating the pipeline and now would allow her successor, John Kerry , and President Barack Obama to make the final decision. “I will refrain from commenting because I had a leading role in getting that process started,” Mrs. Clinton said. “And I think that we have to let it run its course.” Many Republicans have […]