Doha, May 21 (Reporter) Elon Musk, a key sponsor of U.S. President Donald Trump, said on Tuesday that he plans to cut his political spending substantially. Having spent approximately 300 million U.S. dollars to back Trump's presidential campaign and other Republicans, Musk said at an economic forum in Qatar, "I'm going to do a lot less in the future ... I think I've done enough." However, he did not entirely rule out future political contributions. "If I see a reason to do political spending in the future, I will do it." Musk's role as a prominent Trump supporter has spurred protests against Tesla, driving down its sales and stock price. Since Trump's inauguration, Tesla's stock has fallen about 20 percent, despite a small rise of 3.3 percent due to Musk's remarks on Tuesday...////...