It is a risky strategy that could leave her more isolated and unpopular as voters defect to Barack Obama, the new front-runner for the Democratic presidential nomination. Obama, 46, is being tarred as a cultish, messianic figure who talks big but cannot deliver.

Clinton, 60, is being driven into her last redoubts as white women, blue collar workers and Hispanics – her core supporters – have begun to peel away. In public she is adopting a feistier tone and a more populist message against the Illinois senator in a bid to stem her losses.