The outcome was widely forecast. But Hillary Clinton’s overwhelming defeat to Barack Obama in Tuesday night’s “Potomac primaries” nevertheless stung badly and intensifies pressure on her to do something – anything – to forestall the Democratic nomination from slipping out of her grasp.

If, as expected, Mr Obama also wins the primaries next week in Wisconsin and Hawaii then Mrs Clinton will have lost 10 consecutive nominating contests since last week’s almost evenly divided honours in “Super Tuesday”. Mrs Clinton’s senior strategists insist that she still maintains her built-in advantage for the much larger states of Texas and Ohio that go to the polls on March 4.