Longtime Capitol observers believe Ebke, a first-term senator, may be the first Libertarian to serve in the officially nonpartisan Legislature.

Clerk of the Legislature Patrick O’Donnell said Wednesday that he could not think of another registered Libertarian who served, although other senators have had strong libertarian leanings. But because the Legislature is formally nonpartisan, his office doesn’t keep records of past members’ party affiliations.

Michael Knebel, a party spokesman, said that a Libertarian now serves on a City Council in the state, but said Ebke is the first in the Legislature.

Libertarians favor a limited, fiscally responsible government that does not infringe on personal freedoms — “making sure government is out of your wallet and out of your bedroom as much as possible,” Knebel said.

The party has been on and off the ballot since the 1980s, but has qualified as an official political party in the state since 2010. With two statewide candidates receiving at least 5 percent of the vote in 2014, the party will remain on the ballot at least until 2018, Knebel said.

Ebke’s decision to join gives the Libertarians momentum at a key time, Knebel said.

“It is a watershed moment,” he said.