With two major contests in the Democratic nomination race finally approaching, Jonathan Singer takes a look at the latest polling. Singer writes that surveys in Pennsylvania have mixed results. Most show the race close with Hillary ClintonHillary Diane Rodham ClintonBroadway play 'Hillary and Clinton' closing early due to low ticket sales Broadway play 'Hillary and Clinton' closing early due to low ticket sales Facing challenge from Warren, Sanders touts strength against Trump MORE slightly ahead and another poll by reputable pollster SurveyUSA showing the former First Lady up big. The picture is less murky in North Carolina, where Barack ObamaBarack Hussein ObamaProgressive activist: Democratic nominee will 'need to ride a little bit to the center' Progressive activist: Democratic nominee will 'need to ride a little bit to the center' Juan Williams: Trump's incredible shrinking GOP MORE has held double-digit leads in recent polls, Singer writes.