Mayor Rahm Emanuel on Wednesday dumped all over President Donald Trump’s plan to make dramatic cuts in corporate and personal taxes.

Emanuel is a former member of the U.S. House Ways and Means committee, which is responsible for writing and re-writing the nation’s tax code.

He also served as former President Barack Obama’s first White House chief of staff.

On Wednesday, the mayor turned into a bit of a policy wonk as he disputed an element of the president’s proposal that the average Joe may not notice.

“Part of what is in that proposal is the elimination of the deduction of state and local taxes. And that would penalize Illinois and Chicago residents dramatically. So on that level, I’m opposed to it,” he said.

After phasing out the hated $4-an-employee head tax in Chicago, Emanuel also argued that taxes are only part of the reason why individuals, families and corporations choose to locate in a city or even in the United States.

RELATED: Trump proposing tax cuts for companies big and small

Equally important, Emanuel said, is having what he considers to be Chicago’s great strengths: “The best-trained, educated workforce with a university and higher-education system to back that up, one of the best transportation systems and an aviation system that allows every one of the sales reps and operations people to get on a plane and get to where they need to go that day.”

“You can’t be willy-nilly about the taxes. On the other hand, there’s an assortment of things that go into economic growth,” he said.

“I oppose the decision to eliminate the deduction on state and local taxes. But as it relates to economics and business environment, that is not the factor,” Emanuel added.

Mayor Rahm Emanuel (left) joined Great Wolf Resorts CEO Ruben Rodriguez and the company mascot to officially open their new Chicago headquarters. | Fran Spielman/Sun-Times

The mayor raised his concerns after a joining Great Wolf Resorts Inc., a company that runs what it calls the largest family of indoor waterpark resorts in North America, to open the company’s new corporate headquarters in Chicago.

Emanuel also delighted in a federal judge’s ruling that Trump has condemned, blocking an executive order that sought to withhold federal funds from Chicago and other sanctuary cities where immigrants can access city services and live without fear of police harassment.

“We have a welcoming city ordinance. . . . We’re in good company with New York City [and] California. But more importantly, we were on strong legal ground based on other rulings the Supreme Court has made on health care that you cannot coerce a municipality [by] withholding funds based on a policy,” the mayor said.

“The city was not gonna move from a set of policies that reflect our values of being a welcoming city. We weren’t gonna be coerced. We weren’t gonna be blackmailed. We weren’t gonna be punished,” he said. “We’re not only not gonna turn our back on our history. We’re not gonna turn our back on our future. People from around the world and around the country come to this city to achieve the American dream. And the United States government cannot coerce the city, cannot blackmail the city, cannot punish the city into changing its value system.”

Although this week’s ruling was temporary, Emanuel predicted that sanctuary cities would ultimately prevail when a final judgment is rendered, perhaps by the U.S. Supreme Court.

“We are, as a city, not only on strong legal ground, we’re on strong moral ground and I believe it will also be sustained,” the mayor said.

Treasury Secretary Steve Mnuchin and National Economic Director Gary Cohn have described Trump’s plan as reducing the number of personal income tax brackets from seven to three.

Tax rates in those three brackets would be 10 percent, 25 percent and 35 percent. The standard deduction for married couples would double to $24,000. Deductions for charitable giving and mortgage interest payments would remain.