McALLEN, Tex. -- During the first nine months of this year, Sen. Barack Obama raised just $2,086 for his presidential campaign from people who live in and around this border town of stucco bungalows and weed-covered farm lots, and most candidates raised even less. But Sen. Hillary Rodham Clinton, the Democratic front-runner, has already raised more than $640,000 here, and her campaign expects to collect even more. Clinton's success in this unlikely setting is based almost entirely on her friendship with one man, McAllen developer Alonzo Cantu. A self-made millionaire who once picked grapes on the migratory farm labor circuit,...