Bill Clements: Oilman and politician who broke the Democrat stranglehold on Texas

The truly distinguishing feature of Bill Clements was not his outsize Texas personality – complete with a rags-to-riches ascent from oil-patch roughnecker to powerhouse industrialist, a straight-shooting and often acerbic style, and a blithe indifference to what lesser men might consider gaffes. It was that he transformed the politics of the second most populous state in the union, eclipsed today in presidential electoral votes only by California.

Before Clements was elected for the first time in 1978, Democrats had held the office of governor without interruption since post-Civil War Reconstruction. Today, Republicans have a seemingly unbreakable grip on both that job and on state politics in general. No Democrat has been elected to a Texas Senate seat since 1970; since 2003, Republicans have dominated both houses of the Texas legislature, and the state that produced the likes of Lyndon Johnson and Lloyd Bentsen is now home to George W Bush and Bush's no less firmly entrenched successor, Rick Perry. Without exaggeration, Perry could pay tribute to William Perry Clements this week as "the father of the modern-day Texas Republican party."

Few would have predicted as much when he was growing up, the son of a father ruined by the Depression, "broke flatter than a fritter" as Clements later put it. After high school he went to work in the south Texas oil fields before striking out on his own and borrowing money to buy two rusty oil drills. Thus in 1947 was born South Eastern Drilling Company, or SEDCO, which would grow into one of the largest drilling companies in the world before the Schlumberger oil services group bought it in a $1bn deal in 1984.

But Clements was not just a hard-nosed oilman. An avid student of Texan culture and history, he also entered Republican politics, leading Richard Nixon's 1972 re-election campaign in the Lone Star State. Nixon rewarded him by naming him Deputy Secretary of Defense, to run on a daily basis one of the largest bureaucracies on Earth.

During four years in Washington, serving first Nixon and then Gerald Ford, Clements used his managerial acumen to improve efficiency at the Pentagon. And, he liked to boast, although he was a Republican he never lost a funding battle with the Democrat-controlled Congress.

With Jimmy Carter's arrival at the White House in 1977, Clements went back to Texas and, presenting himself as a no-nonsense businessman, embarked on a run for governor the following year. Even though he spent $7m – a fortune at the time – on his campaign and the state Democratic Party was split, few gave him much chance. But in November 1978 he narrowly defeated his opponent, John Hill, to become Texas's first Republican governor since 1874. "I never doubted I would win," he said later.

Clements was unabashed about his methods. "What do you want? A bunch of nincompoops and hardly-ables running the deal?" he responded to critics after picking several businessmen for top state posts. He was Texas-blunt on other issues too: "Don't cry over spilt milk," he advised coastal residents threatened by an oil spill from a well for which his company had leased some of the equipment. But in other ways he defied stereotypes. Though fiscally conservative, Clements struck deals with the Democrat-controlled legislature to raise taxes to attack the state's budget deficit.

And during his first term, Texas started to acquire its modern political contours as conservative Democrats switched to the Republican party, in line with the trend across the South. Under Clements, the state also began to gain its current reputation for toughness on crime, vastly expanding the prison system and in December 1982 carrying out the first execution by lethal injection.

Before that, however, Clements had paid the price for the state's stagnating economy, losing his bid for re-election to the Democrat Mark White. But he brushed off the setback in characteristic style – "Hell, I've drilled dry wells before" – and in 1986 he gained revenge after the economy was struck by the mid-1980s oil bust. This time it was White who was doomed to defeat.

Clements's second term, however, was wrecked by an "only-in-Texas" scandal. During his spell out of office, Clements had joined the board of governors of Southern Methodist University in Dallas (where he had once briefly studied engineering in the late 1930s) and signed off on a scheme to make illegal payments to star SMU football players. When the scheme came to light, the national authorities cancelled SMU's entire season. Soon Clements's involvement became known, and asked by reporters if he had lied, he remarked that "Well, we weren't operating, like on Inauguration Day, with a Bible."

When the re-elected governor next gave a press conference, a group of reporters turned up brandishing Bibles. In football-crazy Texas the episode was a political disaster, and Clements chose not to seek re-election in 1990. But by then, his mark on Texas politics was already indelible.

William Perry Clements Jr, oil industry executive, US government official and Republican politician: born Dallas, Texas 13 April 1917; married twice (two children); US Deputy Secretary of Defence 1973-1977; Governor of Texas 1979-1983, 1987-1991; died Dallas 29 May 2011.