Gov. Rampton entered the University of Utah after selling the family business. He graduated and attended George Washington University in graduate law studies, then graduated from the University of Utah Law School, where he became a "reader" for professor Willis Ritter, later a well-known federal judge in Utah. After finishing his undergraduate degree from the U., Gov. Rampton applied to be administrative assistant to Rep. J.W. Robinson, D-Utah, and moved to Washington, D.C., serving Robinson from 1936 to 1938. Gov. Rampton was elected chairman of the Administrative Assistants Association in a race against Lyndon Johnson's younger brother, Sam Houston Johnson. The young Utahn attended George Washington University Law School at night and on Saturdays.

Even though he still had a year before getting his law degree, Gov. Rampton returned to Utah in 1939 and was elected Davis County attorney, serving from 1939 to 1940. At that time a county attorney didn't have to be a member of the bar. It was a part-time position that paid only $75 a month. Until his election as governor 16 years later, it was the only elective office he ever won.

Gov. Rampton remembered well the first real case he tried as a prosecutor. It involved a man charged with a number of severe traffic violations. The offender was tried before Joseph Sill, father of soon-to-be LDS general authority Sterling Sill. Joseph Sill, at the time, was in his mid-70s, a nonlawyer serving his first term as a justice of the peace. Justice Sill was running for the Utah Senate in 1940 as a Democrat, and Gov. Rampton had also filed for the office, having decided not to run for re-election as county attorney. The defense attorney was a well-known Salt Lake attorney. After Gov. Rampton finished questioning his last witness — and believing he'd done a fine job for a beginning lawyer who wasn't even a member of the bar — he jumped to his feet shouting, "I move all charges be dropped." Sill, duly unimpressed by his Democratic primary opponent, immediately replied, "I second the motion." The defendant was freed.

Gov. Rampton, having decided not to seek re-election as county attorney, instead worked for the Democratic attorney general candidate who promised him a job as an assistant attorney general if he won. At the same time, Gov. Rampton worked for a state Senate seat but not very hard. He thought he had an easy win, but he lost to his Republican opponent by less than two dozen votes. "I learned a valuable lesson. I had more relatives than that who hadn't bothered to vote," he said in retrospect.

He joined the Utah National Guard as an enlisted man in 1932. He rose through the ranks, becoming a sergeant and then a first lieutenant in 1937. When World War II began, he was called up and glad to serve. But he'd had a severe case of pneumonia as a freshman in college — he nearly died — and somehow his Army medical records were mixed up with those of a man who had a bad heart. After only several months of active duty, Gov. Rampton was shipped home as too ill to serve, and Army doctors stubbornly refused to admit they had the wrong records.