Bernie Sanders swept all three Democratic caucuses on Saturday, with decisive victories over front-runner Hillary Clinton in Washington state, Alaska and Hawaii, according to NBC News analysis.
Speaking to a rapturous crowd in Madison, Wisconsin, after his victory in Alaska, Sanders declared his campaign was making "significant inroads" into Clinton's big delegate lead.
The Vermont senator also gave some breaking news to his jubilant supporters.
"OK, are you ready for a news alert? We just won the state of Washington!" Sanders told the crowd to cheers and applause. "That is what momentum is about.
"Don't let anybody tell you we can't win the nomination or win the general election — we're going to do both of those things," Sanders said.
Sanders later notched a big win in the Hawaii caucuses, and has picked up a total of 55 delegates to Clinton's 20 across Saturday's contests so far.
Despite the gains, however, Sanders still significantly trails Clinton in the delegate count. As of Sunday evening, Clinton leads Sanders 1,678 to 1,003.
But the Vermont senator has pledged to keep fighting on, arguing that the states that have yet to vote in the primary represent the most favorable ground yet for his insurgent campaign.
The race now heads to the April 5 showdown in Wisconsin, where the two candidates will battle over a total of 96 delegates.
Although Clinton has not yet wrapped up the nomination, she has increasingly pivoted to a general election message, more often taking explicit aim at the remaining GOP candidates. She also spoke out forcefully in the wake of the terror attacks in Brussels this week, emphasizing her foreign policy experience and contrasting her vision for America's role in the world with the stances of leading Republicans Donald Trump and Ted Cruz.