In 1980, George H.W. Bush edged out Ronald Reagan in the Iowa caucuses 32% to 30%. He lost the nomination to Reagan.
Eight years later, after serving seven years as Reagan’s Vice President, H.W. finished third with 19% of the vote behind Bob Dole who snagged 37% of the vote and Pat Robertson who snagged 26%. He won the nomination.
In both years (1980 and 1988), the contest for the Republican nomination was decided relatively early.