Erpenbach called the situation "a little bizarre" and said he'd rather be home in his bed. But he said he's confident he's doing the right thing for his constituents.

"I can tell you I'm clearly representing the majority of my district, based on the contacts I've had with people," he said.

Erpenbach said he didn't know how long he and the 13 other Democrats would hold out, saying a lot is up to Walker. "It's not like we wanted to do this, but we needed to slow this down," he said.

Erpenbach said he was traveling alone and didn't know the precise locations of the others.

Fitzgerald said: "They understand they have us under a barrel, with the 20 votes."

Walker moving ahead

On Thursday, Walker seemed firm in his resolve to push through his bill, and Assembly leaders were preparing to take up the measure Friday.

Walker said the state is broke and has nothing with which to negotiate. And he called on the senators to return to Madison.

"Their actions, by leaving the state and hiding from voting, are disrespectful to the hundreds of thousands of public employees who showed up to work today and the millions of taxpayers they represent," he said.