In 1966, after three years of study he received his law degree from Loyola University in New Orleans, where he was a member of Delta Theta Phi.
[2] At the time of his marriage, Guarisco was affiliated with the Morgan City law firm Levy, Burleigh, Russo and Bourg.
[2] In a 1974 murder case, Guarisco successfully obtained the first verdict of "Not guilty by reason of insanity" in Louisiana criminal law history.
To win the seat, he defeated State Representative Elward Thomas Brady Jr., of Houma in Terrebonne Parish, who had worked to control the damage from the 1973 Mississippi River floods.
[8] In 1978, Guarisco successfully sponsored a bill to permit physicians in Louisiana to prescribe marijuana for therapeutic use glaucoma or in treatment by chemotherapy.
[9] In 1980, Guarisco ran in a special election for Louisiana's 3rd congressional district, a position vacated by incoming Republican Governor David C. Treen.
The two major candidates were State Representative Billy Tauzin, then a Democrat but later a Republican from Thibodaux and newly turned Republican Jim Donelon of Jefferson Parish, the current state insurance commissioner who had run unsuccessfully for lieutenant governor in the 1979 general election when he was defeated by fellow Democrat Robert "Bobby" Freeman of Plaquemine in Iberville Parish.
Guarisco, considered a social liberal because of his earlier support of the failed Equal Rights Amendment to the United States Constitution, and Bob Namer, then a conservative Democrat, rounded out the four-candidate field.
[11] Treen's predecessor (and successor) as governor, Democrat Edwin Edwards, supported Tauzin, a former floor leader in the House.
In 1981, he was the floor manager for the impeachment and removal of state Senator Gaston Gerald of Greenwell Springs, convicted of extortion.
[6] Prior to 2011, Guarisco was the manager and minority owner of the former Guarisco-Evans Shopping Center located next to the Medicine Shoppe in Morgan City.