For Cronin, the rush has lasted an unprecedented nine terms, six mayors, a zillion hours of contract negotiations, and more than a few death threats.
It all comes to an end tomorrow night, when the 6,500-member District Council 47, American Federation of State, County and Municipal Employees, elects Cronin's successor.
Oh, boy, is he ready. He recently overheard a conversation between two young members in which one asked, seriously, if Cronin were president for life.
"I thought, 'Wow, it has been a long time,' " he says. "I might be getting stale. People can stay around too long - presidents of the United States, governors, and particularly, union leaders."
Dressed in a black T-shirt and black trousers, the buff union man (he bench presses 235 pounds) is sitting in his half-empty District 47 office in Center City. Moving boxes are scattered throughout.
Most of Cronin's personal papers have been given to Temple's labor archives. Old strike posters from such disparate organizations as the NFL Players Union and SEPTA are piled on a table.
"I've pissed a lot of people off," he says quietly. "I have no regrets. Working people have to struggle for any measure of justice in this society, whether it's civil rights, minimum wage, AIDS funding or labor. Nobody gives it to you."
Especially if you don't look the part.
With his trademark straw hat, Cronin bears little resemblance to "the typical union leader who likes to roll up his sleeves and go to war," says Buzz Bissinger, author of A Prayer For the City, a chronicle of Mayor Ed Rendell's 1992-96 first term.
A ruddy Irishman, Cronin says he wears the hat to look cool. The real reason, however, is to protect his punum after a bout with skin cancer five years ago.
Hat or no hat, Cronin "is a great, old-fashioned labor negotiator in the best sense of the word," says former Mayor Bill Green (1980-84). "He cares about his people and fights like crazy for them."
Crazy like a fox. Worldly and well read, Cronin "brought a level of intellect to negotiations that will be very hard to replace," says David L. Cohen, Rendell's chief of staff for 51/2 years.
Judging by his bloodlines, Cronin was genetically destined to be a revolutionary.
His father, Joseph, was a Philadelphia public defender and lifelong champion for the underdog. Among his many arrests was one with Tom at an antiapartheid demonstration in Washington in the mid-'80s.
"That's my idea of a father-son bonding experience," Cronin says.
His mother, Maryann, spent several weeks in a Nevada jail, along with Daniel Ellsberg, for trespassing on a nuclear test site - in her 70s.
And, of course, there's his name, the result of a negotiation (naturally) between his parents.
The elder Cronin wanted his son named after his idol, Common Sense author Thomas Paine, a Revolutionary War hero and Philly transplant. Mom said no.
Mom, a devout Catholic, wanted the baby baptized. Dad, an atheist, said no. They met in the middle: Dad got the name, Mom got the baptism. Amen.
"There was a lot of pressure for Tom to be as Thomas Paine-like as he could be," says his wife, Sandy Dunn, a retired Lower Merion Spanish teacher.
Like his namesake, Cronin is a passionate orator.
When he's firing on all cylinders, "his face turns red and the veins pop out of his neck. I kind of like it," says Ted Kirsch, president of the Philadelphia Federation of Teachers from 1990 to July.
Ironically, Cronin was raised to be a soldier. His stepfather - his parents divorced when he was less than a year old - was a career Air Force officer. Young Tom learned all about guns.
"I had weapons before I had a baseball glove," he recalls. He joined the National Rifle Association and won medals for his target shooting.
After moving around the country every few years, Cronin graduated from high school in Dover, Del., in 1960. At that point, he was ready to enlist in the Marines and go to Vietnam.
Instead, at his father's urging, he moved to Roxborough, where he still resides. The decision wasn't a big hit with Sgt. Stepdad. "I heard he was so ashamed, he told people I was in the CIA," Cronin says.
Over the next three years, he devoured his father's books (including Common Sense), accompanied him to political meetings, met his Quaker friends.
To support himself, he worked at a factory. For fun, he got into boxing. The only white kid in a North Philly boxing gym, he trained with future heavyweight champion Joe Frazier and Bennie Briscoe, among others.
"I was taught that when you get hit, don't get angry," Cronin says. "You'll lose your discipline. Keep a clear head, then move back or to the side." He followed those lessons for the next 40 years.
In 1963, Cronin enrolled at Cheyney State College, a historically black school. (He says he didn't get in anywhere else.) In his freshman year, he was arrested with about 200 other area students at a civil-rights demonstration in Chester.
You always remember your first.
"The cops were beating people and throwing them on a school bus. I got whacked a couple of times and spent three weeks in jail. It was one of my radicalizing experiences."
Faced with seven charges, including aggravated assault and battery with intent to kill, Cronin cut a deal in return for a suspended sentence.
"I look back at my first arrest with great fondness and pride," he says. "Every arrest I've had has been righteous, for causes that needed to be championed and fought for."
Cronin joined the city's workforce in 1970 as an investigator with the Commission on Human Relations. One of the original organizers of District Council 47, he served as president of the local for two years before being elected to the district post in 1980.
James Tate was mayor in 1970, followed by Frank Rizzo, Green, W. Wilson Goode, Rendell and Mayor Street. All Cronin's relationships with Hizzoners have been problematic, to some degree, he says.
"When the mayor is helpful to the people I represent, I'll work with him. When he isn't, I'll fight him. . . . If a union's worth its salt, there should be conflict in contract negotiations. Otherwise, the union's caving."
Dealing with Street "has always been hard," Cronin says, because of their history. During particularly contentious negotiations in the early '90s, when Street was City Council president, the two engaged in verbal warfare.
Street referred to the union leader as "Thomas Pain." He turned his chair around when Cronin entered the negotiating room.
"He wouldn't meet with me. I was furious," Cronin says. "I threatened to take a chain saw and go through the door." Street could not be reached for comment.
"Tom's job was to protect his union, not kiss the butt of the City Council president. John didn't like that," author Bissinger says.
Under Street's administration, however, Phil Goldsmith, his managing director from 2003 to '05, "never got angry at Tom. I never sensed anything personal. The good ones are like that."
Cronin says his worst relationship with a sitting mayor was with Rendell "because of what I perceived as total disrespect for city workers. . . . He got elected on our backs." Rendell could not be reached for comment.
The next mayor (presumedly Democrat Michael Nutter) will have the pleasure of negotiating new four-year deals for the four city unions, beginning in January. The current contract expires June 30.
The dance rarely changes: The unions want benefits; the city wants givebacks. Voices are raised; insults are traded. Both sides are unhappy. The curtain closes.
The burning question is this: How did Cronin manage to hold onto the reins for almost three decades amid all that drama?
"Good drugs," he says with a laugh. "And the ability to take a punch."
Contact staff writer Gail Shister at 215-854-2224 or firstname.lastname@example.org. Read her recent work at http://go.philly.com/gailshister.