TWO well-known Chicago dinosaurs are attracting gawpers right now. One is Sue, the city’s beloved 40-foot-long Tyrannosaurus rex, who is moving from the Field Museum’s main exhibition hall to her private suite on the second floor. The other is Michael Madigan, the Democratic Speaker of the Illinois House, who has represented his district on the south-west side of Chicago for 47 years and been Speaker for 33 years. For the first time in his long career, Mr Madigan is facing calls to resign from members of his own party, because of the way he handled allegations of harassment at his office. Yet this episode has served mainly as a reminder of the extraordinary grip Mr Madigan has on state politics.

Daniel Biss, a state senator, and Christopher Kennedy, a businessman, both Democratic candidates for governor, are leading the charge. Mr Biss called on Mr Madigan to resign immediately as chairman of the Democratic Party of Illinois, another of Mr Madigan’s functions. Mr Kennedy said Mr Madigan “chose to protect his machine political allies instead of the women who were abused by them”, and “he no longer can lead our party.”

Alaina Hampton, a young political consultant, alleges that the Speaker and his entourage tried to sweep her complaints under the carpet when she accused Kevin Quinn, a long-standing Madigan aide, of harassing her for more than five months. Ms Hampton worked for Marty Quinn, Kevin’s brother, a powerful alderman and close ally of Mr Madigan with whom he shares office space in his ward. She is also accusing Mr Madigan’s people of refusing to hire her for a political campaign in retaliation for her allegations.

Few state representatives or aldermen are openly criticising a man nicknamed the “Velvet Hammer”. In 2013 his daughter, who is the state’s attorney-general, pulled the plug on a run for governor because her father was not ready to stand down. Mr Madigan is the longest-serving—and possibly most powerful—Speaker of any state assembly. And, at 75, he shows no sign of wishing to retire.

In his decades in Springfield, he has built a machine that is admirably efficient at getting his candidates into state office. He has been elected 17 times as Speaker, seldom with any challenge from another Democrat (Illinois does not have term limits). In his constituency in Chicago he tends to win with over 60% of the vote. When Jason Gonzales, a political consultant, dared to challenge him in the primaries in March 2016 for his House seat, he retaliated with a campaign of television and radio ads brutal even by Illinois standards.

“Madigan is very much of the old school of machine politics,” says Christopher Mooney of the University of Illinois at Chicago. He is a moderate Democrat of Irish-German extraction who mixes a lack of ideology with a reverence for the Catholic church. After losing the Speaker’s job between 1995 and 1997 when Republicans held the majority, he became almost exclusively focused on winning elections. Local lore says that when he cleared out his office for his Republican rival he left behind a vintage first-aid kit, a not-so-subtle hint at bloody battles ahead.

Mr Madigan has built an unrivalled network of campaign aides and volunteers, who are devoted to him. In April 2013 Alex Clifford, the chief executive of Metra, a regional commuter railway company, wrote in a memo that Mr Madigan had asked him to give a pay rise to one political ally who worked at Metra and a job to another. Two months later Mr Clifford was fired, albeit with a whopping severance package of $871,000. Subsequent investigations cleared Mr Madigan of any wrongdoing, but a report by Thomas Homer, then the legislative inspector-general, published in 2014 by the Chicago Tribune, contained an account of Metra’s chairwoman entering Mr Madigan’s office for a chat and leaving with a yellow Post-it note bearing the names of two workers the Speaker wanted promoted. In another meeting, a longtime Madigan aide who worked as a lobbyist for Metra was spotted leaving the Speaker’s office with two CVs.

Even during the Metra scandal Mr Madigan was able to keep a low profile. This changed after Bruce Rauner took over as governor the next year. The neophyte Republican pursued the Speaker mercilessly after they fell out over passing the state budget. Mr Rauner took to blaming Mr Madigan for the state’s abysmal finances and every other problem, accused him of having shady ties with trade unions and even called him a crook. He also spent millions trying to tarnish Democrats by linking them to Mr Madigan. “Demonising Madigan is one thing the governor has done successfully,” says Kelly Cassidy, a state representative.

Seeing his opponent weakened thanks to the #MeToo movement suits Mr Rauner a few weeks before the primaries for governor on March 20th. “Mike Madigan has spent his three-decade reign as Speaker of the House advancing his own political career at the expense of Illinois taxpayers,” says Mr Rauner, but now “his corruption is finally catching up to him.”

Yet Mr Madigan remains very powerful, and is safer in his job than Mr Rauner. Depending on the outcome of the investigations of harassment on his watch, he might be forced to step down as chairman of the party. But after what is likely to be a resounding victory in the legislative primaries in March (he is running unopposed) as well as the mid-term elections in November, he will almost certainly be re-elected Speaker in January 2019. No serious challenger is in sight. Like Sue the dinosaur, who is moving to a smaller hall, Mr Madigan may just have to get used to a slightly smaller sphere of influence.