One senior adviser to Sen. Bernie Sanders (I-VT) has fallen into despair over his dwindling chances of winning the Democratic presidential nomination following another round of losses on “Mini Super Tuesday.”

Former Vice President Joe Biden delivered a major blow to Sanders with wins in four primary contests: Idaho, Mississippi, Missouri, and Michigan, the evening’s most important race. Sanders only managed to win North Dakota, while Washington’s results remain delayed.

“The god damn plane has crashed into the mountain,” the unnamed Sanders aide, borrowing a line from the 1998 film The Big Lebowski, told Yahoo News.

Sanders opted against delivering a speech to supporters after he lost Michigan and instead flew home to Vermont. Earlier in the day, the 78-year-old canceled a rally in Cleveland, Ohio, due to public health concerns regarding the coronavirus.

One senior adviser to Bernie Sanders delivered a blunt assessment of Tuesday night’s primary results. “The god damn plane has crashed into the mountain." https://t.co/TlcgJIGYG4 — Hunter Walker (@hunterw) March 11, 2020

Biden now holds a delegate count of 823 to Sanders’ 663. A total of 1,991 is needed to secure the Democratic nomination at the party’s July convention in Milwaukee.

Tuesday’s results continue Biden’s sweeping momentum in the Democratic race. A week ago, he took over as the party’s frontrunner after a dominating performance on Super Tuesday, when he won 10 states to Sanders’ four — including Texas.

Both candidates campaigned in Michigan on Monday, a state that will be crucial for the Democratic nominee to win in November. The state voted for President Donald Trump four years ago and was considered one of the key surprise victories that helped him win the presidency over Democrat Hillary Clinton.

The UPI contributed to this report.