[2] Demers began his career as a member of the Chicopee board of assessors.

In 1967, he defeated his fellow assessor Walter Olbrych by 13,668 votes to 9,156 to succeed the retiring Edward A. Lysek as mayor of Chicopee.

It was the first time in Olbrych's 22 years in public office that he had been defeated.

[4] In 1971, Demers was defeated by city treasurer Edward J. Ziemba by 14,760 votes to 7,793.

[5] From 1971 to 1981, Demers was a member of the Massachusetts House of Representatives.