Billionaire Harold Simmons, one of the richest men in America and a major contributor to the Republican Party, has died in his native Texas at 82.
The death, confirmed in a statement by Texas Governor Rick Perry, was first reported on the website of the Dallas Morning News which said he died on Saturday at Baylor University Medical Center at Dallas.
His wife, Annette, told the newspaper Simmons had been "very sick for the last two weeks," and in Baylor's intensive care unit for the last eight days.
She did not give a specific cause of death.
Simmons, currently listed at No. 40 on Forbes' list of the 400 wealthiest Americans, funneled millions of dollars to Republican campaigns with a view toward defeating President Barack Obama last year.
He was widely considered one of the Republican Party's most aggressive donors in 2012 and took advantage of new rules that place few limits on how much money wealthy individuals and corporations can contribute to political groups.
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"Harold Simmons was a true Texas giant, rising from humble beginnings and seizing the limitless opportunity for success we so deeply cherish in our great state," Perry said in a prepared statement.
"His legacy of hard work and giving, particularly to his beloved University of Texas, will live on for generations."
Though he never ran for office, Simmons profoundly shaped the course of presidential politics in 2004 when one of his businesses gave $3 million to the group Swift Boat Veterans for Truth, which helped to undermine Democratic presidential nominee John Kerry by attacking his Vietnam War record.
A pioneer of the leveraged buyout, Simmons and his holding company, Contran Corp, was the largest backer of Texas Governor Rick Perry's failed presidential bid.
Simmons himself gave $100,000 to Americans For Rick Perry, another affiliated group, but later gave $500,000 to Winning Our Future, a Super PAC supporting rival Newt Gingrich as Perry's campaign faded in the polls.
Contran's political action committee also gave $5,000 donations, the legal maximum, to Republican candidates Mitt Romney and Tim Pawlenty.
That approach is common in Texas, where donors commonly spread money around in order to ensure access.
Simmons has been one of Perry's biggest backers during his tenure as Texas governor, a time when his company Waste Control Specialists LLC sought to set up a lucrative nuclear waste dump in the sparsely populated western part of the state. Perry sought to sideline a state commissioner who opposed expanding the scope of the project.
A company spokesman pointed to Simmons's extensive donations to Republicans as evidence that he was not targeting Perry for any special favors.
Simmons's donations were not limited to the political arena. He and his wife had pledged to give more than half of their wealth to charity, joining an effort launched by investor Warren Buffett.
Simmons had also pledged more than $177 million to health research efforts at the University of Texas-Southwestern in Dallas, and another $50 million to Parkland Health and Hospital System, a public hospital in Dallas.
His charitable foundation supports a wide array of causes, including some that might anger conservatives.
In 2010, the Harold Simmons Foundation gave $75,000 to public broadcasting organizations, $2,500 to Planned Parenthood, and $25,000 to Public Campaign, a Washington-based organization that "aims to dramatically reduce the role of big special interest money in American politics."