I’m sorry...I must be stupid. Why wouldn’t they just run the poll at a D+7 instead of reweighting it?
Because that wouldnt give them the result they want. Their random sample is telling them the electorate is R+1 but they either dont believe that, or in this pollsters case, is too stubborn to change his assumptions.
Supposedly, there is no way to know, ahead of time, that the sample taken reflects the expected turnout. So they "assume" a turnout model, and weight the sample according to what they claim is the expected turnout.
Weighting also introduces another assumption, that the DEM vote will be 100% Crooked, and the R vote will be 100% Trump.
Wasn’t D+4 the number in 2012?
Wouldn’t the smart/cautious assumption that turnout be no better for the Dems than 2012?