Five thousand people at his kick off rally in Vermont. Three thousand in Minnesota. The largest crowd of any candidate this year in Iowa. Standing-room-only in New Hampshire. A surprising finish in a straw poll in Wisconsin.

Armed with low expectations and a stopped-clock message that has finally found its time, Sen. Bernie Sanders’ longshot Democratic presidential campaign is resonating with voters more than anyone expected just a few weeks ago.

The latest sign came this weekend in Wisconsin at the state’s Democratic convention. In a straw poll of delegates at the meeting, 49% party officials and activists who cast ballots picked Hillary Clinton as their top choice for the Democratic presidential nominee. No surprise there – Clinton is dominating every poll and has a stronger lead than any non-incumbent presidential frontrunner in modern history.

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But Sanders was within striking distance, just 9 percentage points behind Clinton, capturing 40% of the vote.

It’s just a straw poll, which are far from predictive (ask 2012 Iowa straw poll winner Rep. Michele Bachmann). And only 511 ballots were cast total, according to a tally posted on the blog WisPolitics.

Nonetheless, it shows a desire for an alternative to Clinton and an interest in Sanders among the party’s most committed members, at least in Wisconsin. And the results show that Sanders has, at least for the moment, solidified his place as Clinton’s main rival.

Other Clinton declared and potential challengers didn’t even come close. Vice President Joe Biden and former Gov. Martin O’Malley, who declared his presidential run last weekend, each got 16 votes. Former Sen. Jim Webb got 8 and former Gov. Lincoln Chafee, who also recently declared his run, got 5. Sen. Elizabeth Warren, who is not running, got 4 write-in votes.

Even Sanders’ top strategist, veteran Democratic operative Tad Devine, seemed surprised by the result. “Wow!” he tweeted.

“The Wisconsin straw poll and huge turnouts at town meetings in New Hampshire and Iowa are sending a message that people care about real issues like income inequality and the collapse of the American middle class,” said Sanders campaign manager Jeff Weaver.

Meanwhile, Sanders himself seems to be beginning to “Feel the Bern” – the unofficial slogan dreamed up by some young Sanders fans in Vermont that has been catching on along with his campaign.

In Keene, New Hampshire on Sunday, Sanders struck an unusually confident tone before a standing-room-only audience of between 750 and 1,000.

“Let me tell you a secret,” he said, according to the Keene Sentinel. “We’re going to win New Hampshire.”