ABC News reports:

A planned state Senate vote on slashing Wisconsin public worker pensions and curbing their unions stalled Thursday after Senate Democrats apparently fled the state.

The contentious vote was postponed because the 33-member Senate must have 20 present for a quorum and not a single Democrat attended. There are only 19 Republicans so at least one Democrat must be present for the Senate to open business.

Police have been sent out to look for the wayward lawmakers, the Associated Press reported. A source said it appeared that the Democrats had boarded a bus headed for Iowa.

Sen. Mark Miller, the Democratic minority leader, released this statement on behalf of Senate Democrats: “Democrats believe it is wrong to strip people of their right to have a say in the conditions of their employment and to use state law to bust unions.

“We urge Governor Walker and the Republicans to listen to the people of Wisconsin, talk to the workers and reach an agreement that helps balance the budget while respecting their rights.”

Seriously. That happened. Just now.

UPDATE: The Wisconsin Democrats are apparently at a Best Western resort (a resort!) in Rockford, Illinois. One of their number apparently called into CNN with a list of demands. Mary Katherine Hamm reports:

State Senator Mark Miller, a member of the missing band of Wisconsin Democratic lawmakers who fled Madison Thursday to avoid a vote on a budget bill, called into CNN with the group’s list of demands for Republican Gov. Scott Walker.

Miller, a state senator since 2004, would not disclose where he and his colleagues were hiding out, saying only “we are in what we consider a secure location outside the capital. We are not all in one place at this time.”

Miller’s demands focused on the collective bargaining portions of the bill.

“We demand that the provisions that completely eliminate the ability of workers… to negotiate on a fair basis with their employers be removed from the budget repair bill and any other future budget,” Miller said.

He also demanded legislative oversight on changes to the state’s medical programs, which are targeted for changes in the bill. The bill would also require union members to contribute to their health care and pensions.

Democrats: The Grown-Up Party.

UPDATE II: The Senate majority leader sent law enforcement to round up the erstwhile Democrats, who according to a local station may be on their way back to Madison:

Fitzgerald says they’ve sent law enforcement to bring the Democrats back to the session. They’re issuing a “call of house.” Sergeant of Arms went door to door to find Democratic senators. 27 News went with Sergeant of Arms to every Democratic senators’ office and no one is there.

UPDATE III: Governor Walker just had a press conference, a money quote:

“Show up, debate the bill, offer amendments… but you don’t have a debate if you’re hangin’ out in Rockford.”

Another:

State Sen Jon Erpenbach (D) to WTMJ: WI Sen Dems are “not in the state.” Won’t be back “for a while.”

And:

State Sen Jon Erpenbach (D), on Dems fleeing the state: “We are doing our jobs.”

UPDATE IV: Wisconsin Senate is adjourned for the day.