For a man who had the ear — and trust — of some of the most powerful politicians in Illinois, it was a pretty simple rule:

Always return telephone calls.

But it was a credo that Gene Callahan embraced for more than half a century — from his days as a must-read political columnist to his decades as trusted aide to Sen. Paul Simon and Sen. Alan J. Dixon to his years as a lobbyist for Major League Baseball.

“His hard and fast rules in life were basic: always be honest and always return phone calls,” said Sen. Dick Durbin. “People who lied to him were banished, shunned and rarely redeemed. Those who did not return his phone calls could expect a series of phone calls that would not end until they finally relented.”

He had an unbelievable way of finding people even before cell phones, said Thom Serafin, a political analyst and former reporter who said Callahan was like an uncle to him.

Serafin and Callahan met in Springfield in the 1970s when he was a reporter and Callahan was Dixon’s chief of staff.

“He was an ingenious inspiration for everyone in office,” Serafin said. “He was a walking, talking encyclopedia for Illinois politics.”

Mr. Callahan, father of U.S. Rep. Cheri Bustos and a trusted adviser to a Who’s Who of other Democratic politicians, died Monday.

He was 80.

“Gene Callahan was one of those rare fixtures in the political world – a true gentleman who could work with anybody, any time, to get things done,” said Gov. Pat Quinn.

“It is hard to believe the 40-plus-year ‘Callahan era’ has come to a close. Few of us can remember a time when Gene was not involved in public service. Thankfully, he has instilled those same values in his daughter Cheri Bustos, who has taken his ethic of hard work and honesty to the U.S. Congress.”

Political Consultant Tim McAnarney said he talked to Callahan on the phone nearly three times a day almost every day for 40 years.

“People of all walks of life would call Gene Callahan,” McAnarney said. “He took a great pleasure in helping people.”

Durbin said: “Gene Callahan was my trusted friend. I never made an important decision in my political life without calling Gene. He was totally honest, painfully candid, and completely loyal. You knew that if the world turned on you, Gene would be the last person standing by your side.”

“The Illinois political scene will never be the same without the Pride of Milford, Illinois, Gene Callahan.”

Bustos told Early & Often that her father died around 3:30 a.m. Monday at his Springfield home. The coroner believes cause of death was a heart attack.

Mr. Callahan remained active until the end. He spent Sunday at a political event for his daughter at Norb Andy’s, a Springfield tavern popular with politicians and reporters.

Bustos said her father “soaked it in on his last day,” spending it with his family and supporting her as a congresswoman.

She said the importance of returning telephone calls was one of the many life lessons her father imparted to her.

“Have the decency to get back to people. Be responsive,” she said.

“He didn’t look at things in terms of politics, more in terms of public service,” Bustos said.

Mr. Callahan was a political columnist for the Illinois State Register, which later became the State Journal-Register, from 1957 to 1967.

In 1967, he made the jump from writing about politics to practicing it. He served as a deputy press secretary to Gov. Sam Shapiro and later press secretary and chief of staff to Lt. Gov. Paul Simon.

Starting in 1974, he began working for Dixon, who was then state treasurer. Mr. Callahan stayed with Dixon as Dixon moved up to become Illinois secretary of state and a U.S. senator in 1981.

McAnarney and Callahan met in 1973 when they worked for the state treasurer’s office. McAnarney said Callahan, who was one of his best friends, read six to seven newspapers a day and had an “encyclopedic knowledge of Illinois politics. A constant source of information.”

Mr. Callahan was Dixon’s chief of staff, until Dixon — who died just last month — lost his Senate seat in 1992. Mr. Callahan then spent a number of years as the chief lobbyist for Major League Baseball.

His daughter was elected to represent the Downstate 17th Congressional District in 2012.

“I lost my top spot in his political hierarchy when his daughter, Cheri Bustos, was elected to Congress,” Durbin said. “His pride in her election was the capstone of his career in politics as a trusted adviser to Paul Simon and Alan Dixon.

“Illinois will miss Gene Callahan,” said Simon’s daughter, Lt. Gov. Sheila Simon. “And the Simon family in particular has lost a dear friend.

“Gene served as chief of staff for my dad, a mentor for my brother, and a trusted advisor for me. He was always focused on what was best for the people of our state, not short-term political advantage. His ethical standards were the highest – standards I try to live up to daily.”

Quinn said: “Illinois has suffered two huge losses recently – first former Sen. Alan Dixon, and now the senator’s long-time friend and advisor, Gene Callahan. Our thoughts and prayers go out to his family and the thousands of people whose lives Gene touched during his long and storied life.”

A lifelong Democrat, Mr. Callahan was respected on both sides of the aisle.

“Illinois lost a true statesman this morning with the passing of Gene Callahan,” said Republican Comptroller Judy Baar Topinka. “Gene was passionate about public service. Although he worked in government and politics for decades he was able to rise above partisanship and work with anyone for the good of the order. He was truly one of the good ones. My thoughts and prayers are with his family at this difficult time.”

Bustos said her father never lost his love of making telephone calls. The East Moline Democrat said she believed his last phone call was with her sister-in-law and brother’s widow, Stacy Callahan.

Survivors include his wife, Ann; two daughters, Lynn Callahan Riddley and Cheri Callahan Bustos; a sister, Neta Erdman, and seven grandchildren.

A party to celebrate his life will be held from 2 p.m. to 6 p.m. Friday at Norb Andy’s, 518 East Capitol Ave., Springfield.

“Gene wanted his family and friends to celebrate his life, not mourn it,” according to a family statement. “In lieu of flowers, be sure to vote on Nov. 4.”