After yesterday's Public Policy Polling survey finding that the special election to fill Ted Kennedy's Senate seat was a toss-up, a Boston Globe poll released today finds Democrat Martha Coakley beating Republican Scott Brown by a 15-point margin. Polling a special election is difficult, of course, because it's hard to predict the composition of the electorate. In the PPP survey, 44 percent of those polled were Democrats and 39 percent were independents, while the Globe had Democrats outnumbering independents by a nearly 4-to-1 margin, or 56 percent to 15 percent. But the fact that PPP detected more voter apathy among...