Mr. Sanders’s appearance, before enthusiastic supporters who packed the vast lawn in front of the State House, was marked by an enduring pride in Vermont. Though he hit many of his usual themes, he also checked off the state’s notable moments throughout history: participating in the underground railroad, outlawing slavery, legalizing same-sex marriage.

“Maybe we run in 2020 on a message that says, ‘Cherry Garcia in every freezer,’” he said, in a nod to Ben & Jerry’s ice cream, founded in Vermont, which was supplied free at the rally.

(A campaign aide said Mr. Sanders was appearing this weekend in Montpelier, not Burlington, because “it is a beautiful venue that speaks to his commitment to the state.” Burlington, as it happens, is also hosting a marathon this weekend.)

There is some debate over how effective Mr. Sanders has been as a Vermont official. As Burlington’s mayor, he at times faced criticism for focusing too much on foreign policy. But he also successfully turned the shores of Lake Champlain, much of which had been industrial wasteland, into a bustling, accessible waterfront — an accomplishment his campaign highlighted in a video about his mayoralty that it released on Friday.

Among Vermonters, Mr. Sanders still engenders a strong sense of loyalty, and his presence in the state Saturday was, for many, a welcome sight.

“I believe it’s the last time that we’ll be able to touch him like we usually do without him belonging to the country,” said Brenda Lee LeClair, 55, of Richmond. “We have to be unselfish and give him up.”