Polling in Minnesota's Senate race is unexpectedly close

Polls of Minnesota's Senate race between Democrat Peggy Flanagan and Republican Michelle Tafoya, fielded since the start of August, with Republican pollsters marked with "(R)"

A poll's date reflects its final day of fielding. Pollsters are excluded if they hold a quality grade of "F," per election analyst Nate Silver.
Chart: Andrew ManganSource: New York Times polling database