The polling, at least for now, says Mr. Sanders is not positioned to win by these sorts of margins. He’s in a tight race in Massachusetts. He’s in a tight race in Oklahoma, a state with a below-average black population and a large number of working-class Democrats. There is not much polling in Colorado or Minnesota, but there isn’t much evidence of a blowout there or in neighboring Wisconsin.

Perhaps Mr. Sanders’s best chance of earning a blowout win would be to take advantage of the caucus format, as Mr. Obama did in 2008. Mr. Obama won states like Minnesota and Colorado by two-to-one margins with strength among Democratic activists and a superior organization. This was a big part of how Mr. Obama held a clear advantage in pledged delegates despite being even in the popular vote — and Mr. Sanders would certainly benefit from a similar phenomenon.

This could happen. It depends, to some extent, on why Mrs. Clinton struggled in caucuses last time. Was it because she was poorly organized? Was it because her working-class supporters were less likely to vote? Was it because caucuses are just vastly more liberal? Was it because caucuses attract only the most well-informed and committed voters — the sort who make campaign contributions? The first two explanations might bode well for her this time, since she fares better among affluent voters and she’s better organized than last time. The latter two might augur better for Mr. Sanders, who has received far more small donations than Mrs. Clinton.

In an interview last week, Ben Tulchin, a pollster with the Sanders campaign, did not seem optimistic about his candidate’s chances in closed caucuses. He said that there was opportunity to organize, but that such caucuses were difficult for independents, who would have to change their party registration to participate, and young voters — two sources of strength for Mr. Sanders. “They’re not tailor-made for us,” he said. “It’s still structurally challenging for us to do well.” He was more optimistic about open caucuses, in states like Nebraska and Alaska. Whether Mr. Tulchin’s thoughts reflect the campaign’s views or represent an effort to lower expectations is hard to say.

What’s clear is that modest Sanders wins in Massachusetts, Minnesota, Colorado and Oklahoma would not indicate that he had much of a chance to overtake Mrs. Clinton’s delegate lead.