House Speaker Michael Madigan is the last delegate to the 1970 Illinois constitutional convention who’s still in politics. It was his first elected office, and his introduction to Springfield, the state capital he now dominates. As a delegate, Madigan helped draft the document that enshrined the flat income tax into Illinois law. Now, 50 years later, voters may upend it in favor of a graduated tax. 

In 1970, a flat tax was the only way to get a constitution ratified. The year before, Republican Gov. Richard Ogilvie had introduced the state’s first income tax, an unpopular move that would end up costing him his job. The voters, who had to approve the new constitution, weren’t going to open the door to even higher rates than those they'd begrudgingly begun to pay.

“To allow a graduated rate would have been a move away from the status quo — a move the delegates were not willing to make,” wrote Joyce W. Fishbane and Glenn W. Fisher in Politics of the Purse: Revenue and Finance in the Sixth Illinois Constitutional Convention.

As delegate Frank Cicero of Evanston put it, “it is apparent in this Convention — and I am convinced in the state at large — that it’s necessary to remove the issue of a graduated income tax in order to reach agreement in this Convention on a revenue article.”

Chicago Democrats, of whom Madigan was one, were opposed to a flat tax, but they ultimately went along with it to get the Constitution passed.

In 1970, a graduated tax wasn't as important to the economic well-being of Illinois as it is today. The middle of the 20th Century was a period of unprecedented income equality in the United States.

Shortly thereafter, though, the incomes of the wealthy and the middle class began to diverge sharply. In 1970, the wealthiest 1 percent of Americans received 9 percent of wage and capital income. Today, they receive around 20 percent. According to a study by the State Budget Crisis Task Force, a flat tax has made it impossible for Illinois to capture the ultra-wealthy’s income gains.

Last year, Madigan took a step toward reversing the acts of his youth by getting a constitutional amendment for a graduated income tax through the General Assembly. The Fair Tax Amendment, as Gov. J.B. Pritzker calls it, will be on the ballot in November, requiring approval from 60 percent of voters.

Ironically, Madigan himself may be an obstacle to its passage. The amendment’s opponents have long argued that it amounts to a blank check for Democrats to raise tax rates as high as they want. Now that Madigan has been implicated as Public Official A in the ComEd influence-peddling scandal — and is facing calls from fellow Democrats to resign — that argument is more powerful. The Illinois Policy Institute, a libertarian think tank and the state's foremost opponents of the graduated tax, is already tying the amendment to the Speaker’s alleged corruption.

“Illinois’s system consolidates unprecedented power,” says the Institute’s Austin Berg. “For years, we’ve worked to highlight how that power results in other serious policy issues, including the pension crisis and out of whack spending priorities, which lead to politicians asking for tax hikes year after year. That includes the latest push for a progressive income tax. It’s not surprising that five state lawmakers implicated in corruption scandals, including Madigan, also voted to put this tax hike on the ballot.”

Plenty of progressives who love the graduated tax also loved seeing Madigan, a fossilized vestige of the Daley Machine, exposed as a crook. But as the Tribune noted, “Republicans who oppose the change have already adopted the campaign mantra of asking voters if they trusted sending more tax dollars to a Springfield run by Democrats led by Madigan.”

Madigan is at once the most powerful and the most hated elected official in Illinois. But unless you’re one of the 108,000 residents of his Southwest Side district, you don’t get to vote for or against him.

Meanwhile, the fair tax is the most important issue on the ballot this fall. It shouldn’t be tied to Madigan. The best way to prevent that from happening may be for Madigan to resign — not just from the speakership, but from his House seat. (After all, nobody believes that giving up his title would mean foreiting his control over the House. Having already won the Democratic primary, Madigan could use his power as committeeperson to replace himself with some 13rd Ward lackey.)

Madigan helped saddle his party with a flat income tax. Now, the best thing he can do to reverse it may be to get out of politics altogether.