New Morning Consult National Poll: Harris 51 Trump 45

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40. A Margin Of Error Of 1%?

That’s kinda bizarre. The extra expense involved for getting it down that low, it had to be super spendy. Not really worth the extra expense, either.

Here’s an excellent explanation of polling and MoE from Penn State’s College of Science web site:

… you again find that as the sample size increases, the margin of error decreases. However, you should also notice that there is a diminishing return from taking larger and larger samples…the amount by which the margin of error decreases is most substantial between samples sizes of 200 and 1500. This implies that the reliability of the estimate is more strongly affected by the size of the sample in that range. In contrast, the margin of error does not substantially decrease at sample sizes above 1500 (since it is already below 3%). It is rarely worth it for pollsters to spend additional time and money to bring the margin of error down below 3% or so. After that point, it is probably better to spend additional resources on reducing sources of bias that might be on the same order as the margin of error.

Emphasis added.