Tarrant then transferred to Saint Michael's College on a basketball scholarship and was a first-team All-American in his senior year.

He led the Purple Knights to the Final Four of the 1965 NCAA Men's Division II Basketball Tournament, where they were defeated 93–70 by the University of Evansville, who had Jerry Sloan and Larry Humes, both All-Americans.

In the consolation game of the same tournament, Tarrant played against Phil Jackson of North Dakota, who went on to fame as a player, coach, and executive in the National Basketball Association.

By 2005, IDX had contracted with thousands of doctors' offices across the country, and provided computer technology for many of the United Kingdom's medical centers.

In 1994, Tarrant donated $5 million toward the construction of St. Michael's College's student recreation center, which is named in honor of his parents.

On September 12, 2006, he won the Republican nomination, defeating US Air Force Lt. Col. Greg Parke and marijuana legalization activist Cris Ericson.

Tarrant's campaign was remarkable for its saturation of radio and television with a serial biography of the candidate and attack ads of Sanders.