Legislation creating the tax incentive structure businessman Dan Gilbert needs to erect a 52-story skyscraper in the footprint of Detroit's former Hudson's store got final approval in the state Senate on Tuesday.

And nearly nobody noticed.

In what may have seemed unimaginable just a year ago or so, the Republican-controlled Legislature passed sweeping legislation that was initially sold as something Detroit wanted.

Or, more specifically, something the billionaire owner of Quicken Loans wanted — to help underwrite an eye-catching change in Detroit's skyline, and to keep fueling downtown revitalization.

Mayor Mike Duggan sounded astonished that the legislation got sent to Gov. Rick Snyder's desk before Memorial Day as he boasted about its passage Tuesday at the Downtown Detroit Partnership's annual meeting inside Eastern Market's Shed 3.

“Dan Gilbert dreamed this thing up six months ago and led a coalition with a lot of people here and people around the state,” Duggan said.

The legislation creates a first-of-its-kind tax capture mechanism for developers to help finance redevelopment of long-time brownfield sites with a portion of new tax revenue generated on the revitalized property.

Under the five-bill package, developers could keep up to 50 percent of the income tax generated by individuals working or living in the redeveloped site for up to 20 years.

The legislation sets a $40 million annual limit on the amount of tax revenue developers can capture at all of the sites under the Transformation Brownfield Program.

The legislation narrowly tailored a requirement that a brownfield project in a city of more than 600,000 residents — Detroit is the only such city in Michigan — must contain a minimum investment of $500 million in order to qualify for the tax incentives.

Bedrock LLC, the real estate arm of Gilbert's downtown empire, has pegged the cost of constructing a towering 734-foot building at $775 million. The tower would contain 1.2 million square feet of above-ground real estate, 250 residential units and 700 below-ground parking spaces.

The Downtown Development Authority board has given Bedrock until Nov. 1 to finalize a development deal.

Gilbert's representatives thought they might need that long to get the Legislature to pass the bill.

Instead, the legislation sailed through the Legislature with wide margins of 85-22 in the House and 32-6 in the Senate.

Snyder plans to sign the bills, his spokeswoman said.

“This legislative package opens the door to new economic development projects that will be truly transformational for communities across Michigan and offers the potential for thousands of new jobs," Snyder said Tuesday in a statement.

But unlike past prolonged battles in Lansing over Detroit's lighting authority, creation of a Regional Transit Authority, the 2014 bankruptcy "grand bargain" and last year's bailout of the city school system, this Detroit-centered legislation got buy-in from out-state legislators.

At the beginning of the year, supporters were trying to rebrand the so-called "Gilbert bills" by emphasizing how the tax-capturing legislation could help fund the cleanup of urban eyesores from Jackson to Muskegon, Petoskey and Sault Ste. Marie.

“We spent a lot of time dispelling the myth that Dan Gilbert was driving it,” said state Sen. Ken Horn, R-Frankenmuth, who sponsored the legislation. “It was a case study in good bipartisan cooperation."

As the MiThrive Coalition sought to statewide support for the legislation, Duggan has been on the road talking up Detroit's turnaround before chambers of commerce in Brighton, Grand Rapids, Marquette, Mount Pleasant "and some cities I’ve never heard of.”

The mayor told city business leaders on Tuesday that "attitudes have changed" about Detroit.

Duggan said it used to be that when he spoke out-state, people would come to him afterwards and reminsce about their roots in the city.

After a speech last week in Mount Pleasant, Duggan said he was greeted with different feedback from local business owners.

“The first one said, ‘My son is working in the city of Detroit. The second one said, ‘My niece is working in the city of Detroit," Duggan said. "The third one said, ‘My grandson just graduated to apply for a job in Detroit. Can you help him get a job?'”

The mayor, who is running for re-election this year, sees a change in the trajectory of Michigan's outbound college graduates headed for his city.

"It’s changing right now and people around the state of Michigan are seeing Detroit as the place where their children and grandchild will go for opportunities," Duggan said.

Gilbert is capitalizing on the attitude change with his grand plans for the site of the former Hudson's department store — one of many symbols of Detroit's late 20th Century decline.

After the House passed the legislation last week with little drama, the downtown real estate mogul reiterated that passage of the legislation will be a big boost to Detroit.

"We look forward to the sight of numerous cranes in the sky of Detroit and across Michigan," Gilbert said in a statement on Twitter. "Time to put our shovels in the dirt!"

Chad Livengood: (313) 446-1654

Twitter: @ChadLivengood