Thursday in Dallas, a son of Texas will be laid to rest. The death Sunday at age 94 of former Gov. William Perry Clements Jr. ended a storied life of achievement and service.

For a man who changed the politics of Texas—and thereby of America—he started inauspiciously. As a high school senior in Dallas during the Great Depression, Clements learned his parents were broke and unable to send him to college. He lit out for south Texas to become an oil-field roughneck, sending most of his pay home for his family.

He spent a dozen years bouncing around the oil business until 1947, when at age 29 he began his own business, grandly called Southeastern Drilling. Starting with borrowed money and two used rigs, he built Sedco into the world's largest drilling contractor, pioneering offshore drilling techniques that made its rigs a common sight around the globe.

In December 1972, President Richard Nixon named him deputy secretary of defense. In the next four years he would play a key role in resupplying Israel in the Yom Kippur War, help create the all-volunteer military, modernize the nation's submarine deterrent, and father the cruise missile.

Then in 1978, he ran for governor of Texas. It was an improbable goal. Texas was heavily Democratic, and the last Republican governor had been elected in 1869, when federal troops guarded the polling places.

Clements was an improbable candidate. Gruff, sometimes abrasive, and partial to weirdly colored plaid sport coats, he was not given to political niceties or backslapping. But he had an authenticity that Texans liked. In an astonishing upset, they elected Clements by 17,000 votes out of nearly 2.4 million cast.

He became the strongest modern Texas governor, except perhaps for John Connally in the 1960s. But Connally had a legislature almost wholly Democratic. Clements governed with only 26 Republicans in the 181-member legislature.

Karl Rove is a former senior adviser and deputy chief of staff to President George W. Bush. He is a Fox News contributor and author of "Courage and Consequence" (Threshold Editions, 2010). To continue reading his column in The Wall Street Journal, click here.