WASHINGTON (Reuters) - U.S. Senator John McCain said on Monday that he personally backs Washington’s decades-old “one China” policy and that no one should “leap to conclusions” that President-elect Donald Trump would abandon it. “I do not respond to every comment by the president-elect because it may be reversed the next day,” McCain told Reuters when asked about Trump’s statement over the weekend that the United States did not necessarily have to stick to its position that Taiwan is part of “one China.”  But McCain said that “somebody should hold China responsible” for its behavior with regard to Taiwan, Hong Kong, island building in the South China Sea and “propping up” North Korea. Trump has drawn an angry response from Beijing for his comments as well as his recent telephone call with the president of Taiwan. 