Winning decisive victories in Florida, Illinois, and Arizona, Joe Biden amassed a formidable lead over Bernie Sanders on Tuesday night, under the shadow of the spreading coronavirus pandemic.

The former vice president defeated the Vermont senator by wide margins in every state, which meant that by the evening’s end he had amassed 1,068 pledged delegates to only 771 for Sanders, according to ABC News. That is a lead many analysts regarded as almost mathematically insurmountable, requiring Sanders to win 60 percent of all delegates in the remaining states. But with many state parties postposing the contests that remain, it isn’t clear how or when Biden will be able to reach a majority before June.

In Florida, Biden won by nearly 40 points. He took Illinois by almost 24 points and Arizona by nearly 13 points, as Sanders underperformed his 2016 vote in all three states. Sanders offered no hint on Tuesday night as to whether he will heed increasing calls by Democrats for him to concede the primary and begin to build party unity against President Trump — or continue his campaign until the convention in July. Uncertainty caused by the national health emergency has led his own surrogates and advisers to suggest that he should press on.

In Illinois, progressive candidate Marie Newman won her second challenge to conservative Democrat Rep. Dan Lipinski, making him the first member of Congress to lose his seat in 2020.

Biden spoke on Tuesday night briefly after the results began to come in.