A vote by New York utility regulators approving nearly half a billion dollars in annual subsidies over the next two years for a trio of ailing nuclear plants was a victory for Exelon Corp., which owns two of the plants and is in talks with Entergy Corp. to buy the third. Now the polarizing debate moves back to Chicago-based Exelon's home state, where the clock continues to tick on a similar measure to aid a pair of nuclear plants ticketed for closure each of the next two years. Exelon announced plans to shut the Clinton and Quad Cities nuclear plants in mid-2017 and -2018, respectively, at the expiration of their commitments to run. The company has said the plants -- and jobs and taxes they provide -- can still be spared. But doing so requires assurances that they won't continue to sustain millions of dollars in annual losses.