New Morning Consult National Poll: Harris 51 Trump 45

[GB_RN]

44. Without A Doubt...

Larger samples increase the accuracy. It’s the expense vs diminishing returns on the margin of error.

To get a sample size of 1500 responses, the polling agency probably calls about 50k. Not worth the effort or expense to go beyond a 3% MoE.

The polling agency will weight population groups differently to account for the sample of a particular population’s responses being higher or lower than what they think is representative of that group’s actual size. Every polling outfit has their own population models and so, weighs each group differently. This can account for marginal differences in results between agencies…unless it’s a partisan polling house, such as Rasmussen. These guys weigh groups so as to get results that are more favorable for their candidate. That’s why 538 downgrades those polling houses, or, even better, doesn’t use their results at all.

Hope that makes sense.