Senator Patty Murray has ignited a fresh political firestorm, accusing Elon Musk of contributing no more to the US Social Security system than a well-paid 'electrician'. The Washington Democrat's critique of the world's first trillionaire highlights the widening chasm in the American tax code, where payroll levies stop for high earners long before they reach the stratosphere of billionaire wealth. Murray took to X on Sunday to label the situatio…