By Howard Fischer, Capitol Media Services

Gov. Doug Ducey wants to boost the taxes paid by Arizonans by $180 million or more when they file their tax returns this spring.

But he insists it’s not a tax hike – an assertion that Rep. J.D. Mesnard, whose district includes part of Gilbert, disputes.

The governor plans to conform Arizona’s tax code to changes enacted in federal law.

Those changes took effect last year and are reflected in the new federal income tax forms that people across the country will be filling out between now and April 15.

Conforming to those changes – including what’s deductible – makes it easier for Arizonans to prepare their own taxes so they don’t have to make additional calculations.

And that extra cash? Ducey proposes to add it to the state’s “rainy day fund,’’ a special savings account for emergencies and for lawmakers to tap when there is a sudden unexpected drop in revenues.

That account now stands at about $460 million, less than 5 percent of the state general fund budget.

“It’s an elegant solution,’’ gubernatorial press aide Patrick Ptak said of funneling the new tax revenues into the state’s bank account.

Mesnard blasted the move, saying, “It’s a tax increase and the largest one in modern history.’’

Mesnard pointed out that Ducey’s plan would increase the taxes Arizonans owe, as they no longer could take those tax deductions they have been using for years. And fewer deductions, quite simply, means a more expensive bottom line for many.

That, said Mesnard, is an unfair “windfall’’ for the state at the expense of its residents.

While Mesnard won’t be speaker this coming session, he will still have an important voice in whether the governor gets his way. He will be chairing the Senate Finance Committee, through which all tax bills are supposed to pass.

What’s behind all this is that, under current Arizona law, taxpayers use the federal definition of “income’’ as the starting point for state tax forms. That’s the figure on line 37 of the federal Form 1040.

In most cases, the deductions allowed under state law mirror those permitted under federal law. But the measure approved by Congress earlier this year allows fewer deductions and subtractions.

For example, the new federal law modifies mortgage interest and home equity deductions, a maneuver that, if Arizona follows suit, means $50 million more paid by state taxpayers.

Congress did something that is not in Ducey’s plan: offset the reduced deductions.

First, the federal law reduced tax rates overall. Second, it increased the standard deduction for individuals from $6,350 to $12,000, and double that for couples filing jointly.

That makes the loss of federal deductions less painful as more taxpayers will find it unnecessary to itemize.

But Ducey would leave Arizona income tax rates where they are now, ranging from 2.59 to 4.54 percent depending on income.

And the governor has no plans to increase the state standard deduction for individuals, leaving it at about $5,200. So Arizona taxpayers end up with the worst of both worlds: Fewer deductions they can itemize and no chance to make up the difference with an increased state standard deduction.

The bottom line is that Ducey’s conformity plan would cost taxpayers anywhere from $180 million to $200 million.

“The feds did not pass this as a windfall to state governments,’’ Mesnard said. “They passed this to be a windfall for taxpayers and we’re undermining that.’’

Mesnard said Arizona lawmakers should consider doing what the feds did to keep taxes from going up here, including decreasing tax rates, adjusting the tax brackets and increasing the state standard deduction.

He also charged that Ducey purposely waited until the last minute – right before state tax forms are set to be printed and mailed out – to corral lawmakers into approving his plan.

A Ducey spokesman said his boss is willing to consider eliminating the tax hike – eventually. But any change would affect only the 2019 income taxes due in early 2020.

Mesnard said he’s not convinced that once the state starts taking more dollars from its residents that it will ever give them up.

“If the end result of his administration is that everybody in Arizona is paying more in taxes than they were before he came in, I don’t want that to be my legacy,’’ he said of Ducey. “That’s why I’m going to fight against it.’’