Stew was born, raised and educated in Wright county. He served 15 years on the Dows Community School Board and earned his Bachelor of Arts degree in Accounting from Buena Vista College.

He was elected to the Iowa House for two terms from 1990 to 1994 when he was elected to the Iowa Senate. He served eight years as the Senate Majority Leader, from 1998 until 2006. He did not seek reelection in 2006.

He served two years in the U.S. Marine Corps and was promoted meritoriously four times. Stew and his wife, Vicki, live in Clarion and have two sons, one daughter, and five grandchildren.