Some of the nation’s most influential environmental groups are softening their longstanding opposition to nuclear power, marking a significant shift in the antinuclear movement as environmentalists’ priority shifts to climate change. The change is lowering one of the biggest political hurdles facing the nuclear power industry in the U.S. and comes at a critical time, as several financially struggling reactors are set to shut down. “Because the historical context is that these groups were opposed to nuclear, their absence on the opposition front is noticed,” said Joe Dominguez, executive vice president for governmental and regulatory affairs for Exelon Corp. EXC 0.20 % , the biggest owner of nuclear plants in the U.S. “I think it’s pretty significant.” Nuclear power, which emits no greenhouse gases, provides roughly 20% of U.S. electricity and 60% of carbon-free […]