In truth Mr Obama’s problems extend well beyond the confines of the capital’s Beltway. The president’s headache is that his winning majority resembles the hamlet in “Brigadoon”. It exists all right, twice sending him to the White House. But, like that Highland village, it is hard to see or touch most of the time. (...) The magic at the heart of Mr Obama’s two victories was his ability to expand the electorate itself, mobilising sporadic voters who shun politics most of the time, notably the young and minorities. Now that he is no longer on the ballot, his loose coalition risks being no match for the intense ideologues who fight and oversee Washington’s partisan battles.