Three western U.S. states - Alaska, Hawaii and Washington - are holding Democratic presidential caucuses Saturday in the run-up to the Democratic convention.
Former secretary of state Hillary Clinton is the front-runner with a commanding lead in the delegate count, but Vermont Senator Bernie Sanders refuses to quit and in some places is a formidable opponent of Clinton.
Clinton, in a speech Wednesday after the deadly attacks in Brussels, focused her attention on Republican candidates Donald Trump and Ted Cruz and what she called their "reckless" foreign policies.
"We need to to rely on what actually works, not bluster that alienates our partners and doesn't make us any safer," Clinton said.
Sanders, who is very popular with "millennials" (- generally, people born from early 1980s to 2000 -) and first-time voters, has said "We need a political revolution."
Analysts say Saturday's trio of caucuses may favor Sanders because caucus contests tend to attract the most active liberal Democrats. In addition, Sanders is heavily favored by young voters who were key in placing President Barack Obama in the White House twice.
Clinton still needs 672 delegates to secure the nomination. Sanders needs more than twice that many, with 142 up for grabs Saturday toward the goal of 2,383.