His family had a social democratic history, reportedly his grandfather had moved from Berlin to Kassel due to Chancellor Otto von Bismarck's Anti-Socialist Laws.

[citation needed] Son of a city councilwoman, Börner joined SPD in 1948, and was elected chairman of Kassel area Socialist Youth of Germany – Falcons.

While in Bundestag, he was appointed as Parliamentary State Secretary to the Federal Minister of Transport Georg Leber in Kiesinger cabinet on 12 April 1967, he retained the post in the first Brandt cabinet until resigning on 4 February 1972, after being chosen by chancellor Willy Brandt to replace Hans-Jürgen Wischnewski as the party's federal executive director.

However, two weeks later, Minister President of Hesse Albert Osswald resigned on 16 October following a financial scandal involving public bank Helaba, and 45-year old Börner was chosen by SPD to succeed him as Minister President, so he resigned his Bundestag mandate and took over the state level social-liberal coalition, which was also in power at the federal level.

On 11 May 1981, his Deputy Minister President, Heinz-Herbert Karry (FDP) was assassinated by far-left Revolutionary Cells terror organization.

As Minister President, Börner was critical of the city of Lahn in central Hesse, calling it "rubble" (Scheißdreck).

Lahn had been created under a 1976/77 state administrative reform by the merger of the cities of Giessen and Wetzlar, which his predecessor Osswald had been a supporter of.

The coalition would ultimately prove to be short-lived, when in February 1987, it broke down due to disputes over operating license of Alkem fuel element factory in Hanau, so Börner dismissed Fischer from his post, and a new election was held on 5 April 1987, where Börner did not run again and was replaced by his Deputy Minister President Hans Krollmann as SPD candidate.

[7][8] During the Runway 18 West protests at Frankfurt Airport in 1980s, Börner said that during his construction worker days, the troublemakers would have been hit with roof battens.

[10] Börner died of cancer at the age of 75 on 2 August 2006[11] and was survived by his wife Carola (married since 27 December 1950) and three children, sons Olaf and Fritjof and daughter Heike.