Washington (CNN) -- As angry teachers in the Midwest shut down more than a dozen school districts in protest Thursday, Republican officials across the nation have made teachers' unions "public enemy No. 1" in a battle to trim budgets and rewrite the rules on how unions and states work together.

In Wisconsin, Ohio, New York and New Jersey, governors are taking on the unions -- who they see as guilty of demanding excessive benefits and causing out-of-control waste -- in their quest to cut spending and regain control over the educational system.

Some feel overly generous union contracts are busting state budgets, and many are using the current fiscal crisis to do something about it.

"I'm attacking the leadership of the union because they're greedy, and they're selfish and they're self-interested," New Jersey's Republican Gov. Chris Christie told a conservative conference Wednesday.

Wisconsin Gov. Scott Walker, also a Republican, is pushing a plan to gut almost all union rights for teachers. He wants to monitor how much money they earn and make them pay a greater share of pension and health care costs, all while limiting their ability to bargain collectively.

Late Thursday, state Democrats were boycotting a vote to turn that plan into law by literally fleeing the capital to make sure the GOP-controlled state Senate did not have enough members present for a quorum.

In Ohio, a historic union powerhouse state, Republican Gov. John Kasich is pushing a similar plan through his state's GOP-controlled legislature.

In New York, independent Mayor Michael Bloomberg is trying to eliminate 4,666 teachers' jobs in an attempt to save money, and New York Democratic Gov. Andrew Cuomo, who has long desired to bring unions under control, wants to cut $1.5 billion in state aide to schools to help keep his budget afloat.

Many school districts used federal stimulus dollars to make up shortages in state funding -- a short-term fix for a systemic problem. But that stimulus funding is running out.

Teachers across the country are angry at what they perceive as being scape-goated. In Wisconsin, more than 100,000 public employees and supporters made that clear by marching on the state Capitol and holding a giant sick-out, effectively shutting down classes in 15 school districts.

"We think there should be a vibrant middle class in America and collective bargaining is the best way to guarantee it," said Mary Kay Henry, International President of the Service Employees International Union, who said she is proud of the Wisconsin demonstrators. The protests prove people want to preserve a fair middle-class wage, she said.

"We think our wages and benefits should not be the ceiling for working people in the country. It should be the floor," Henry said, adding that the only weapon the middle class has left against wealthy corporations is the union.

"To kill off 52 years of collective bargaining is crazy," said John Matthews from Madison Teachers Inc., a union representing 2,700 teachers in the Wisconsin city. He said Republican efforts are less about fiscal responsibility and more about killing off the union altogether.

On Wednesday, President Obama told WTMJ-TV in Milwaukee that what's happening in Wisconsin appears to be more of an assault on unions than a move toward fiscal responsibility.

"I think it's important not to vilify them or to somehow suggest that all these budget problems are due to public employees," the president said.