New Harvard Poll Shows Harris With a 31-Point Lead Over Trump (with young voters)

[Self Esteem]

4. No. It just means crosstabs are not to be trusted.

There's a difference between a poll specifically sampling a demographic, as the Harvard Poll does here, and the crosstabs of a poll sampling that demographic.

Crosstabs generally have a high MOE because they're a subset of the population polled. Quinnipiac polled 1,728 likely voters.

I don't have the total breakdown of what percentage of those polled were 18-34 but in 2020, 18-29 made up 17% of the electorate and 30-44 23%, so, let's just assume 18-34 was 20% of the poll.

That means it's just 346 total from that group.

Which likely has a significant MOE.

Couple that with the fact Biden did worse among 30-44 (+6) than he did 18-29 (+24), his lead among 18-34 was probably well below the +24 he received...likely closer to +15 or so, which is likely where Harris is at nationally. Add the MOE (which is frequently +/-10 on crosstabs and her lead could be +13 among this group ... which is a lot closer.

The Quinnipiac Poll might be an outlier but the fact other polls show the race tightening makes me thin it probably is closer to what we're seeing than not.