Dead heat. That's what Wisconsin is staring at in the race for governor, with Gov. Scott Walker and Democratic challenger Mary Burke neck-and-neck heading into the November election, according to the latest Marquette University Law School poll released Wednesday. Among registered voters, Walker led Burke, 46% to 45%. Among likely voters, Burke led Walker, 47% to 46%. "The bottom line is that nothing has statistically changed from May to July," said Charles Franklin, the poll director. "We're seeing a dead heat in the race, well within the margin of error." "As the race really heats up with advertising and back...