(CNN)The next wave of teacher walkouts and demonstrations is about to begin.
Public school educators in Arizona are scheduled to walk out Thursday, and some of their counterparts in Colorado will be at the state Capitol on Thursday and Friday in hopes of getting more funding from legislators.
Teachers in other states, including North Carolina, are either planning their own demonstrations or watching developments closely.
Educators in many states have been rising up against what they say is chronic underfunding, some of which dates to recession-era cuts. They've been energized by teachers in West Virginia, who landed a 5% pay raise last month after a nine-day strike, and walkouts in Oklahoma and Kentucky.
Arizona walkout set for Thursday
Arizona teachers have been agitating for weeks for better pay and more overall dollars for education -- and while the governor says he's pushing for a raise, educators say the plan isn't enough.
Members of the state's education association voted last week to walk out on Thursday. It's unclear how long the walkout will last. The Arizona Educators United grassroots coalition said 90 districts are expected to close Thursday, with between 30,000 and 50,000 educators making a stand.
Earlier this month, Gov. Doug Ducey announced a proposal to raise teachers' pay over the next three years, to what would amount to a 20% total raise by the 2020-2021 school year.
Ducey also proposed to restore education funding from recession-era cuts, by $371 million phased in over the next five years.
But Arizona Educators United had called for 20% pay raises for teachers by next school year, and to completely restore education funding to 2008 levels. The coalition and the Arizona Education Association say funding levels are $1 billion below that of 2008.
The average pay of Arizona teachers in 2017 -- $47,403 -- ranked 44th in the nation, and the state ranked 48th that year in per pupil spending, according to the National Education Association.
As in other states, teachers in Arizona say cuts to general education funding stops districts from keeping up with textbooks, supplies and technology. Low pay and funding also hurt teacher recruitment and retention, leading to teacher shortages and unwieldy class sizes, they say.
Ducey has said he still is pushing his plan to legislators, and on Monday he told Phoenix radio station KFYI that he didn't understand why teachers would walk out with that proposal in play.
"I don't know why the leaders would say that they're going to strike when we're delivering for the teachers on what we believe they deserve," Ducey told KFYI. "I can't understand that. But whatever the leaders in that movement are doing, I don't think they're really representing the teachers that are there for their kids every day, that are there for their parents."
Some schools may attempt to have classes Thursday, should they have enough teachers and staff willing to ignore the walkout, and substitutes. But dozens of school districts say they intend to close should the walkout happen as scheduled, CNN affiliates in Arizona have reported.
Colorado: Some schools closing Thursday and Friday
Last week, one Colorado school district closed as a few hundred educators went to the Capitol in Denver to rally for more funding. Two gatherings at the Capitol this week are expected to be much bigger.
At least 25 districts are closing either Thursday or Friday as thousands of teachers, school staff and their advocates are expected to go to the Capitol, the Colorado Education Association said.
Denver Public Schools, which has canceled Friday's classes, said the state funds education at more than $2,000 per student less than the national average. "That is short-sighted and wrong. Our state needs to dramatically increase our investment in education, and all of our voices play a vital role in this effort," the superintendent said.
Some of those 25 districts already had teacher work days planned for then, so classes wouldn't have happened anyway. But a majority of them are closing because enough educators called in to take personal days -- and the districts didn't have enough substitutes to carry on, CEA Vice President Amie Baca-Oehlert said.
"(Educators) are going there to say, 'I am here to be a voice for my students who for too long have been chronically underfunded," she said.
While state budget writers, according to the Denver Post, have set aside an additional $100 million for education funding, teachers say that is not enough.
Among the issues:
-- Education funding: Colorado effectively has underfunded its schools by $828 million this year alone, the CEA says, because the state hasn't kept up with a state constitutional mandate passed last decade to increase funds each year by at least the rate of inflation.
Raising taxes to make up that money isn't easy, because the state's 1992 taxpayer bill of rights demands that voters approve any tax hikes.
The CEA says teachers it recently surveyed reported spending an average of $656 yearly on school supplies and expenses for students.
-- Teacher pay: The CEA says Colorado educators' average pay dropped by more than 17% when adjusting for inflation over the last 15 years. In 2017, Colorado ranked 31st in the country for average teachers' salary, according to the National Education Association.
Low funding and teacher pay, the association says, is making the job less attractive to college graduates and prodding teachers to leave the profession early, and led to a shortage of fully qualified teachers.
-- Pension reform: The CEA is keeping an eye on a bill that would try to reduce an unfunded liability in the teachers' pension plan. At one point, the proposal would have raised teachers' retirement age from 58 to 65, an excessive jump, CEA President Kerrie Dallman said. But an amendment this month changed that to 60. The bill still is making its way through the House.
North Carolina: 'Enough is enough'
North Carolina's education association is urging teachers to take a personal day on May 16 -- the day the General Assembly reconvenes -- to rally at the Capitol in Raleigh for greater funding and higher salaries.
Teachers' concerns there run the gamut: Too little pay, overall funding that is below where it was before the 2008 recession, and class sizes that are too high, North Carolina Association of Educators President Mark Jewell said.
It's not immediately clear how many schools, if any, will close.
Jewell blames the state's Republican lawmakers, who control the Legislature, for shrinking revenues by lowering the state's corporate and personal income tax rates in the past few years.
"They're starving our school districts. Our local school districts are trying to decide whether to hire an extra remediation (employee) or get toilet paper in the bathroom," Jewell said.
"We're just standing up and saying, 'Enough is enough.'"
The nonpartisan Institute on Taxation and Economic Policy said the state would have $2.8 billion more in annual revenue if legislators had not changed the tax system that existed in 2013. Gov. Roy Cooper had said improving education funding is a priority.
North Carolina ranked 39th in average annual teacher pay in 2017 -- $49,970, or nearly $10,000 below the national average, for the state with the country's 10th highest public school student enrollment, the National Education Association says. That's $2,000 more than in 2016, when North Carolina ranked 41st.
Salaries have recently risen by a few thousand dollars for entry- and mid-level teachers, but the levels at which the most experienced educators are paid have barely risen since 2008, Jewell said.
Utah: Waiting for a gas tax increase
In Utah, no statewide action is planned at the moment -- but labor tranquility could hinge on whether voters pass a proposed gas tax increase in November, the state's education association says.
Like many states, Utah saw its public school funding fall after the recession. By 2015, school funding per student was 14.6% below 2008 levels, when adjusted for inflation, the Center on Budget and Policy Priorities says.