Not even Vermont Republicans can resist Bernie-mania. 

According to a new poll conducted by the Castleton Polling Institute, Sen. Bernie Sanders (I-Vt.) is tied for first place in the presidential race among Vermonters who identify as Republican or leaning Republican. The poll, conducted over the past three weeks, found that Sanders, businessman Donald Trump and retired neurosurgeon Ben Carson each drew 12 percent of the GOP vote. 

"He's the native son, so you expect a lot of support," institute director Rich Clark, who conducted the poll, says of Sanders. "But I didn't expect it to be as high among Republicans."

To be sure, Sanders is hardly walking away with the Republican vote. More than twice as many Vermont GOPers — 28 percent — say they're undecided. The rest are split between a fractured field, including Wisconsin Gov. Scott Walker, who drew 8 percent, and former Florida governor Jeb Bush, who drew 6 percent.

Not surprisingly, Sanders, who recently overtook former secretary of state Hillary Clinton in polls of New Hampshire and Iowa Democrats, performed even better in Vermont among Democrats and independents. Sixty-five percent of those who identify as Democratic or lean Democratic said they backed Sanders, while 14 percent supported Clinton. Among Vermont independents, 39 percent support Sanders, nearly 20 percent support Trump and 7 percent support Clinton, the poll found.

"We see outsiders surging all around," Clark says. 

Overall, 48 percent of Vermonters say they hope to see Sanders in the White House — but they're not so sure it's gonna happen. Forty-six percent say they expect Clinton to win the Democratic nomination, compared to 27 percent who think Sanders will. Twenty-six percent expect former Florida governor Jeb Bush to win the Republican nomination, compared to 21 percent who think Trump will. 

"Most people are saying it's going to be Clinton-Bush, like the pundits have told us," Clark says.

Results from Castleton's poll were first released Wednesday night during a Republican debate-watching party at Rutland's Paramount Theatre, as the Rutland Herald's Rob Mitchell first reported. The event was the first in a series called Project 240 — cosponsored by Castleton University and the Paramount — designed to increase civic engagement ahead of the 2016 elections. 

The poll's overall margin of error was plus or minus 4 percent, though the margin much higher for subsamples, such as Republicans or Democrats. 

See Castleton's full results below.

Castleton Polling Institute's Sept. 2015 Vermont presidential poll