Noah Karvelis, an elementary school music teacher and the founder of Arizona Educators United, said he was sympathetic to the disruption that widespread school closings would cause students and parents. But, he said, that should not forestall a walkout.

“If we maintain the status quo, that is way worse than missing a couple of days of school,” Mr. Karvelis said at a news conference outside the union headquarters in Phoenix. “The biggest disservice any of us could do for our students right now is to not act in this moment.”

Across Arizona, tens of thousands of teachers, parents and students, clad in red, participated in protests outside schools on April 11. Gov. Doug Ducey said he was “impressed” by the movement, which calls itself #RedForEd. He promised to provide teachers with a 20 percent raise by 2020, and to restore school budgets to pre-Recession levels over the next five years. He said he could do so without raising taxes, because the state’s economy is improving and existing state programs could be cut.

But many teachers rejected that plan, or said they distrusted Mr. Ducey, a first-term Republican.

“You don’t rob Peter to feed Paul,” said Kassandra Dominguez, who teaches kindergarten and first grade in the Pendergast school district, near Phoenix. “That’s so wrong, and I wouldn’t want that money.”

Alternate proposals for raising school budgets include increasing an education sales tax from six-tenths of a cent to one cent, or closing corporate tax loopholes.

The average teacher salary in Arizona is about $47,000 per year, according to the National Center for Education Statistics. But starting salaries are much lower, and many teachers leading the protest movement are in their 20s and 30s.

Ms. Dominguez, 27, earns $38,250 per year, and says that because of low education budgets, she has had to pay out of pocket, or raise money from private donors, to buy her students science supplies, chairs and snacks. She voted in favor of a walkout. Her district had lost a total of $1.6 million over the past five years because of budget cuts, according to administrators, and the school board had come out in favor of the #RedForEd movement.