Louis and Mary are my wife's great-great-grandparents
It always pays to pay close attention to neighbors and other potential family members. In this case, the desired family was that of Louis and Mary Desmarais (listed as Demarah). It turns out that a sister-in-law of Louis' was living with him (additional research indicated Mary Desmarais was a Draulett/Drollette before her marriage).
Joseph and Sarah Demarah (Desmarais) listed directly after Louis are Louis' parents.
This census was very legible (fortunately!)
Page 22, Clinton County New York 1880 Census, Enumeration District Number 6.
The scan below is the right hand side of the page. To match up the lines.
Louis Demarrah is the first laborer listed asn was born in New York of Canadian-born
These images were obtained from the set of census images available at Ancestry.Com