In Washington, a progressive-leaning state that Sanders carried by a massive margin in 2016, two recent polls — both fielded after Super Tuesday — show Biden erasing the Vermont senator’s advantage. Biden led narrowly in each, though within the margin of error.

If a loss in Michigan would suggest a weakening of Sanders in the Rust Belt, an upset in Washington hours later would suggest a total crumbling of his base.

“I could see it going either way,” said Sandeep Kaushik, a Democratic consultant who is based in Washington and unaffiliated in the presidential campaign. “The last week has completely reshaped this race. …the momentum coming out of Super Tuesday.”

Sanders is still widely considered likely to win. But a Biden upset – which once seemed almost unthinkable – would no longer be shocking, according to more than half a dozen strategists working in Washington or with experience in that state. And the race is likely to be closer than originally expected, no matter who carries the state.