Sen.Bernie Sanders won a decisive victory in the Nevada caucuses on Saturdayevening, propelling him toward South Carolina and the Super Tuesday primariesas his rivals faltered. Incomplete results showed Sanders with nearly 47percent of the vote, while former Vice President Joe Biden trailed with about20 percent and Pete Buttigieg, the former mayor of South Bend, Indiana, pulledabout 15 percent.

Surveysat the caucuses showed that the self-proclaimed democratic socialist prevailed amongnearly all demographic groups – especially Hispanic voters, whose support wascrucial in Nevada, and young voters. Sanders won in every age cohort exceptthose over 65. He won among voters with college degrees and those without. Andas promised by his campaign, Sanders appeared to have expanded the party baseby drawing in thousands of first-time caucus participants.

After CNN and the Associated Press declared him the winner, Sanders held a massive rally in San Antonio, Texas: “In Nevada we have just put together a multigenerational, multiracial coalition,” he said, “which is going to not only win in Nevada, it is going to sweep this country.”

The Washington Postreports that his momentum is making many Democrats nervous – especially those running for the House and Senate in contested states. Despite Sanders’ apparent lead over Trump in national polls, some Republicans gloated.

“The Democrats’ embrace of socialism is going to cost them their majority [in the House],” said Rep. Tom Emmer (R-MN), who chairs the National Republican Congressional Committee. “Bernie is about as good a contrast as we could have ever hoped for.”