Lightning rod-capitalists Charles Koch and his brother David have added to their already substantial empire, plunking down more than $5 billion on acquisitions in the past year. New additions like inkmaker Flint Group and PetroLogistics go well with what the Kochs already have. Charles has been chairman of Koch Industries since 1967, overseeing massive growth of the now second biggest private company in America, which owns oil pipelines, refineries and manufacturers of building materials, paper towels and even Dixie Cups.The Kochs are concerned not only with profits but with politics, too. They've opened up their big checkbooks in an effort to help Republicans retake the Senate. The Kochs, say Sen. Harry Reid (a Democrat), are "actually trying buy the country." But then they go ahead and do something that confounds critics. Like backing Libre, a fast-growing group aimed at gaining Latino support for limited government, or giving $25 million to the United Negro College Fund.