Do you really believe that if the election were held today Cory Booker would best Trump by 5 points? Buttigieg?
Too bad they don't post the internals. But lucky for you all you have me! Here they are:
From the pollster:
Responses are reported for 1,214 self-identified registered voters with a margin of
sampling error of +/- 3.5 percentage points, including the design effect. The survey
includes 503 Democratic or Democratic leaning voters with a margin of sampling error of +/- 5.4 percentage points.
So, they interview 1214 people, including 503 Dems. Now most polls show that party affiliation breaks down roughly (give or take a few) 31% Dem, 30% Rep and 38% Ind
. Independents, even though are the largest block, typically end up breaking the same way as party affiliation does so Independents are expected to break apx 52%-48% Dem-Rep give or take.
But this poll starts off with 41.4% Dem. That is not balanced anywhere close to the way the electorate identifies. This means they not only oversampled Dems they undersampled either Reps or Inds or both. Notice how they word their "margin of error" - the poll does not have a MOE of 5.4%, that is the margin of error among those who claim to be Dem affiliated!
So if you wonder how is it that, according to Quinnipiac, only 1% of respondents say they follow Booker's campaign but somehow he defeats the sitting president by 5% now you know - over-sample the Dems by 30%!
There is an interesting subset of data, they asked the same questions back in 2015 - Biden or Trump or Sanders or Trump. Trump does better now than he did in 2015's polls.
I might add, 12% Black and 33% Hispanic for the incumbent may seem like a landslide But in reality Dems need to do better than that to hold the line. Races are very close, obviously, close enough to elect Trump over Clinton, and close enough to throw Congress back and forth between the two parties several times in the last decade. Dems losing 3% of the black vote and 8% of the Hispanic vote is not good for Dems.
I won't try to reverse engineer the numbers, but if Biden is only ahead by 13% when the poll is cooked 30% in his favor tells you all you really need to know.