Boner was born in East Nashville, traditionally a politically-active part of the city. A multi-sport star at East Nashville High School, from which he graduated in 1963, he subsequently entered the fields of teaching and coaching, and for two years was basketball coach at Trevecca Nazarene College (now University). He graduated from Middle Tennessee State University in 1967 and received a master's degree from the former Peabody College in 1969. He also became a popular and respected high school sports referee. In 1970 he was elected to the Tennessee House of Representatives, a part-time position, for the first time, serving until 1972.

Leaving the field of education, he became a bank official at First American National Bank (now part of AmSouth) and enrolled in the former YMCA Night Law School (now Nashville School of Law), a school specializing in part-time, mid-career students. He later (1978) graduated from this institution, but never took the bar exam to be admitted to the practice of law. (Many years later, a story in The Tennessean claimed that this was due to an agreement made when he was caught cheating on the school's final exam and that this would not be publicized if he did not apply to take the bar examination, verifying a rumor that had long been heard in the Nashville legal community.) While employed at the bank, Boner was again elected to the State House in 1974. He moved to the Tennessee State Senate in 1974 He then made the decision to enter the Democratic primary against incumbent Fifth District Congressman Clifford Allen in 1978.

Several other persons had also decided to challenge Allen, a long-time Nashville political figure who appeared to be in declining health and who seemed vulnerable. Shortly before the deadline for candidates to withdraw from the race,Allen suffered a massive stroke. All of Allen's opponents except Boner withdrew from the race, apparently out of concern for "kicking a man when he's down." When Allen died on the day after the withdrawal deadline, Boner was virtually unopposed for the nomination, facing only a write-in campaign that went nowhere. This was tantamount to victory in November, as the Republicans had lost interest in a district they hadn't won since 1874. He was reelected four times with no substantive opposition.

Boner's tenure in Congress was largely uneventful. He established a reputation for a staff devoted to excellent constituent service, and otherwise as a moderate Southern Democrat backbencher, whose largest legislative accomplishment was a bill recognizing "National Sewing Month", something which subsequent opponents would later point to with glee. In 1986, he came under investigation by the House Ethics Committee for his close relationship with a government contractor.

In 1987, Nashville Mayor (and former Fifth District Congressman) Richard Fulton was prevented from running for a fourth term. Boner quickly jumped into the race, seeing an opportunity to come home, and also to end the investigation. He was opposed by a large field, notably managed health care executive Phil Bredesen. Boner and Bredesen finished first and second respectively; the Nashville charter requires a mayor to be elected by a majority, so Boner and Bredesen as the top two finishers met in a runoff. Boner won, largely by emphasizing that he was a Nashville native and Bredesen was a Northerner (he was born in New Jersey and grew up in Upstate New York).

Shortly after becoming mayor, Boner's personal life came to the forefront. Already thrice-married, with his current wife being a former law school classmate, Boner nonetheless announced his engagment to Traci Peel, an aspiring entertainer. He proceeded to purchase a large, ostentatious engagement ring for her (the stone later proving to be a cubic zirconium). The story became a sensation, and Boner and Peel appeared jointly on the then-popular Donahue television program, on which Peel sang and Boner displayed his considerable skill with the harmonica. Later, in a Tennessean interview, Peel announced that Boner was capable of "seven hours of passion". Many, perhaps most, Nashvillians were appalled at how this seemed to live down to the worst possible stereotype of their city, and Boner's political future, at least for the time being, was destroyed. (Boner eventually received a divorce from his third wife, Betty, and married Peel. Their marriage was short-lived and Boner subsequently married a fifth wife, who has since made public allegations of adultery against him.)

Boner did not see re-election in 1991; given the furor over his marital life, it is highly unlikely he would have been reelected had he chosen to run. He then took several jobs which many saw as rather humiliating for a former Congressman and mayor of a major city, such as managing a pallet factory in nearby Kentucky, restaurant manager, and even delivering Yellow Pages phone books. He then re-entered politics, again being elected to his former seat in the state legislature where his career began. He then ran for the office of Davidson County Register of Deeds, an unglamourous administrative courthhouse position, and was soundly defeated in the Democratic primary (which always decides the election in a city where Democrats dominate every level of government). He did not seek re-election to the legislature and appears to have left elective politics for good.

Boner subsequently returned to education. He was the last prinicpal of the former Tennessee Preparatory School, a former state-run residential school in Nashville for orphaned, neglected, and abused older children and teenagers, before the decision was made to close the institution. He subsequently became a government teacher at Franklin High School in Franklin, Tennessee, just south of Nashville.

Boner also hosted a nightly television talk show, entitled Prime Talk, on Nashville's WNAB-TV in the mid-1990s.