In 1967, he was elected as a democratic precinct captain, graduating from Purdue University that same year.
After graduating, he joined the Indiana Air Force Reserves and trained as a nurse.
Grubb worked at a bank in Michigan City, Indiana, but returned to his Covington farm in 1974.
Grubb has been a leading advocate for agricultural interests and was the prime sponsor of organ donor legislation.
While the registration in his district is evenly divided, Grubb consistently receives over 60% of the votes.