Bernie Sanders looking for caucus hat-trick to narrow gap on Hillary Clinton

Bernie Sanders is pushing for a hat-trick of wins in today's Democratic presidential caucuses in Hawaii, Alaska and Washington state, hoping to stoke a spring comeback against commanding front-runner Hillary Clinton.

The left-wing Vermont senator spent much of the week on the West Coast, trying to build his enduring support among liberal activists into a Saturday sweep that could help him narrow a gap of 300 delegates won in primaries behind Mrs Clinton - about double the margin that then-Illinois senator Barack Obama held over her in the 2008 primaries.