As a state senator, Barack Obama gave $100,000 in state money to a campaign volunteer who failed to deliver on a plan to create a botanic garden in one of Chicago’s most blighted neighborhoods. ….. what was supposed to be a six-block stretch of trees and paths is now a field of unfulfilled dreams, strewn with weeds, garbage and broken pavement. Kenny B. Smith, whose nonprofit group got the money, said it was spent legitimately, mostly on underground site preparation. But he admitted Thursday that the garden is a lost cause because other government money never came through.