PHOENIX — Top Republican legislative leaders filed suit Monday to block implementation of the voter-approved tax on income of the wealthiest Arizonans.

The lawsuit filed in Maricopa County Superior Court contends the Arizona Constitution allows only the Legislature to impose a new tax, and then only with a two-thirds vote.

“Because Proposition 208 did not meet either requirement, its new tax was not constitutionally enacted,” the lawsuit says.

Arizona officials have certified Joe Biden’s narrow victory over President Donald Trump in the state. Democratic Secretary of State Katie Hobbs and Republican Gov. Doug Ducey stood up for the integrity of the election even as lawyers for Trump were across town Monday arguing without evidence to nine Republican lawmakers that the election was marred by fraud.

The Invest in Ed measure, approved by voters Nov. 3 by a margin of 51.7% to 48.3%, earmarks the proceeds for education funding.

The lawsuit says the measure seeks to exempt the money raised from a constitutional cap on how much schools can spend. It says a statute — even one approved by voters — cannot override what is in the Arizona Constitution.

Attorneys for the challengers also say that the amount of spending the Invest in Ed initiative would require exceeds the amount of revenues that would be raised by the new 3.5% surcharge on incomes above $250,000 for individuals and $500,000 for married couples filing jointly.

Finally, the lawsuit says it illegally ties the hands of state lawmakers by telling them they cannot use the new revenues that would be raised — about $940 million a year — to reduce education spending elsewhere.

That provision in particular gets the attention of lawmakers who agreed to sign on to the lawsuit filed by the Goldwater Institute, including House Speaker Rusty Bowers and Senate President Karen Fann.

“Proposition 208 restricts their ability to appropriate funds for other legislative priorities,” wrote attorneys in the case.

“These legislative leaders further understand that despite the authorities vested in their offices and position, they are powerless under Proposition 208 to divert funds from the general fund, each with a supermajority,” he said. And that, the lawyers said, limits their ability not just to reduce state taxes but also to respond to emergencies and “eliminate educational programs that are no longer necessary or are deemed ineffective.”

The litigation seeks an injunction order barring any implementation or enforcement of the ballot measure until there can be a full-blown hearing.

A separate lawsuit against the measure also was filed Monday, by Ann Siner, founder of My Sister’s Closet, and retired Maricopa County Superior Court Judge John Buttrick.

Invest in Ed backers are expected to fight both lawsuits.

The Arizona Constitution makes the people co-equal with the Legislature when creating law, said attorney Roopali Desai, who represents the Invest in Ed initiative. And that means they have the same powers as lawmakers, even if the elected legislators disagree, she said.

In fact, in some ways the powers of the people are superior, because a constitutional provision bars lawmakers from repealing what voters have enacted. Lawmakers can make only changes that “further the purpose” of a voter-approved measure, and only with a three-fourths vote of both the House and Senate.

Invest in Ed, put on the ballot with a petition gathering process, was pushed by the Arizona Education Association and allied groups seeking to restore cuts that have been made to K-12 funding in the past decade. They say that per-student aid has not kept pace with inflation and student growth.

Half of the funds are earmarked for schools to hire teachers and classroom support personnel, such as librarians, nurses, counselors and coaches. The dollars also could be used for raises.

Another quarter is for support services personnel, including classroom aides, security personnel, food service and transportation.

There’s also 12% for grants for career and technical education programs, 10% for mentoring and retaining new teachers in the classroom, and 3% for the Arizona Teachers Academy to provide tuition grants for students who go into education careers.

Foes, led by the Arizona Chamber of Commerce and Industry, argued there was no guarantee that the cash would go to teachers and salaries.

They also pointed out that it would raise the state’s top income tax rate, now 4.5%, to 8%, which they said would be one of the highest in the nation. They argued that would be a damper on economic development.

But David Lujan, director of the Arizona Center for Economic Progress, pointed out that the only people affected would be those whose taxable income — after all deductions and credits — would be above $250,000 for individuals and $500,000 for couples.

Foes also questioned how much of the cash would wind up in the classroom.

They pointed out that the most recent report by Auditor General Lindsey Perry said just 54.7 cents of every dollar go into direct classroom expenses.

But as Perry’s report pointed out, there is more to that story.

One is that figure does not include other necessary instructional support like librarians and teacher training, nor guidance counselors, nurses, speech pathologists and social workers. And Perry said that, on average, Arizona schools spend less on administrative expenses than the rest of the country.

Other challengers in the suit brought on behalf of Fann and Bowers include other Republican lawmakers and the owners of three businesses who say their income exceeds the $500,000 threshold and would be affected by the new law.

No date has been set for a hearing.

Become a #ThisIsTucson member! Your contribution helps our team bring you stories that keep you connected to the community. Become a member today.