Kristi Noem made headlines last month when a thief snatched her purse inside a Washington, D.C., restaurant and made off with $3,000 in cash, prompting a question: Exactly how much money does the homeland security secretary have? About $5 million, Forbes estimates, after analyzing property records and financial filings. The root of the fortune begins 1,200 miles away from the nation’s capital, in eastern South Dakota, where waves of grain fill the landscape and houses pop up every once in a