Bob Perry, age 79
Est. net worth: $650 million
Source of wealth: Perry Homes, one of America's top homebuilders
2012 favorite: Has given $3.2 million to Rick Perry's gubernatorial bids, but sat on Mitt Romney's 2008 "Texas Leadership Team" and poured $500K into a Romney 2012 super-PAC
Dark-money potential: Extreme. In the 2004 cycle, he gave $4.45 million to Swift Boat Vets for Truth and $3 million to the Bush-aligned Progress for America Voter Fund. In 2006, he spent $5 million creating a free-market 527 group and gave $9.5 million to the Karl Rove-associated super-PAC American Crossroads.
Grab bag: He bankrolled every member of the Texas Supreme Court, which held up a couple's lawsuit claiming their Perry-built home was defective.
Harlan Crow, age 62
Est. net worth: Hundreds of millions
Source of wealth: Real estate; Crow Holdings
2012 favorite: Has given $180K to Rick Perry's gubernatorial campaigns since 2004—plus millions to state and national conservative causes. But Crow Holdings bundled $25K for long-shot GOP contender Jon Huntsman.
Dark-money potential: High. Crow, who sat on the founders' committee of the anti-tax think tank Club for Growth, gave $125K to the Swift Boat Vets circa 2004. He's also given nearly $900K to Texans for Lawsuit Reform and donated $500K to help the wife of Supreme Court Justice Clarence Thomas start a tea party group.
Grab bag: The gardens at Crow's $24 million estate feature statues of notorious historical figures like Mao, Stalin, and Gavrilo Princip—the assassin who sparked World War I.
Harold Simmons, age 80
Est. net worth: $9.3 billion
Source of wealth: Owns Contran Corporation (metals, chemicals, and waste management). Dubbed the "king of Superfund sites," he's lobbied Texas legislators to let him bury low-level radioactive waste despite water contamination risks.
2012 favorite: Has given $1.8 million to Rick Perry's gubernatorial bids since 2001; gave $100K to Perry's presidential PAC in 2011
Dark-money potential: Extreme. Besides doling out more than $1.9 million to Texans for Lawsuit Reform, Simmons has given $2 million to American Crossroads and $3 million to the Swift Boat Vets.
Grab bag: He was once sued by his family for allegedly involving them in illegal campaign donations.
Robert Rowling, age 57
Est. net worth: $4.7 billion
Source of wealth: Owns TRT Holdings (oil exploration, fitness, and Mexican dollar stores)
2012 favorite: Has donated to Tim Pawlenty, Mitt Romney, and Rick Perry
Dark-money potential: Extreme. The former Bush Pioneer prefers "a pretty low profile" and has donated $5.3 million to American Crossroads. He's also given generously to state and national gopers—including $295K to the National Republican Senatorial Committee since 2007—and $362K to Rick Perry's gubernatorial bids.
Grab bag: In 2010, San Francisco franchises of Rowling's Gold's Gym denounced his donations to American Crossroads, which supports anti-gay candidates.
Sam Wyly, age 77
Est. net worth: $1 billion
Source of wealth: Tech investments starting with University Computing Company in 1963; also cofounded Maverick Capital, an $11 billion hedge fund
2012 favorite: He and his late brother, Charles, have given Rick Perry at least $440K since 2000. So far, nada to 2012 candidates.
Dark-money potential: Moderate. The brothers and their spouses have leaned mainstream GOP, giving $2.5 million to Republicans for Clean Air, $1.3 million to the RNC, $380K-plus to congressional GOP PACs, and $75K to the Republican Governors Association over 20 years. Also gave five figures to at least six Texas members of Congress.
Grab bag: Sam's fighting 2010 charges that he and Charles conducted insider trading and socked away more than $500 million in illegal offshore accounts.
One more biggie: "Black Gold for the GOP" profiles Trevor Rees-Jones, a top Texas GOP donor whom you've probably never heard of. Also check out, "How to Win Friends and Influence Elections," which charts the rarified social/charitable orbit shared by Dallas' top GOP power players.