Blüm was the only cabinet member who served in his function for all sixteen years of Helmut Kohl's time as Chancellor of Germany.

[7] During this time, he was a founding member of the local Boy Scouts affiliation, the Deutsche Pfadfinderschaft Sankt Georg.

[9] In 1967, he received his doctorate of philosophy (PhD) in Bonn with the dissertation Willenslehre und Soziallehre bei Ferdinand Tönnies.

[11] His greatest political success was the introduction of long-term care insurance (Pflegeversicherung) in 1995,[2][5] after those reform plans were hotly and controversially debated in the Bundestag.

Blüm adhered to Christian values and belonged to the left wing of the generally centre-right CDU.

[13] During his time in office, Blüm held out and pushed back against demands by fellow CDU politicians to raise the federal retirement age from 65 to 70.

[14] A popular quotation attributed to him is "Die Rente ist sicher" (loosely translated as: "Pensions are safe"),[a] based on the governmental slogan he wielded in 1986: "Eins ist sicher: Die Rente" ("One thing is safe: pensions").

[2] This quotation quickly gained notoriety in Germany and became a popular target for comedy, as well as a cynical reference that would be used by his opponents and critics for years to come.

[17] As a consequence, he was targeted by Scientology advocates, who would claim that the organization was a victim of religious discrimination in Germany.

[18] Despite his good relationship with Helmut Kohl, Blüm criticized his handling of the CDU donations scandal.

[4][25] He commented in a guest article for the German weekly Die Zeit in March 2020 about his new life in a wheelchair due to his paralysis, in which he compared his position to that of a puppet whose strings were pulled so that its parts dangled incoherently in the air: "Like a thief in the night, disaster broke into my life in the form of insidious blood poisoning".