Rounding out the top five: Mexican telecom titan Carlos Slim and Russian oil magnate Vagit Alekperov.

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William Dore, an oil-services magnate, and Foster Friess, a wealthy mutual-fund manager, are the principal donors to Rick Santorum's.

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Oil and metals magnate Viktor Vekselberg set aside business Thursday night to raise funds for, of all things, a California state park.

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These included everyone from railway magnate Collis Huntington to oil mogul Edward Doheny to the embodiment of power, Los Angeles Times publisher Harrison Gray Otis.

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