A reader writes: "Where Obama has campaigned (NOT Michigan and Florida), Senator Clinton's maximum victory margin was 6 percent (Nevada). Neither Obama nor his organization was active in Michigan or Florida, so counting them as Clinton 'victories' (at least by those margins) is deceptive. According to the latest polls, [Obama] is behind an average of only 6 points nationwide. Here in Massachusetts, it appears the margin has shrunk from 37 to seven points. Don't give up on Senator Obama yet."