| Renamed said: And I'll post my periodic reminder that all of these polls use "likely voters". That means people that have already voted in the previous election. They do not include new voters or previously disinterested voters. |
Quick correction: Some of the polls use "likely voters", not all. If you head over to 538, you'll see they post "LV", "RV" or "A" next to the poll's sample size to indicate whether it was conducted with Adults, Registered Voters or Likely Voters. This is actually why 538's forecast is more left leaning than RCP's for example. The likely voter population in this cycle is expected to be more blue than the registered voter population, so they adjust for that. That also means that as we get closer to the election day and more polls switch from RV to LV, we are expected to see Kamala getting a small boost in polling numbers.
You're right though that they don't just ask who is a likely-voter, they make a determination based on several questions they ask. Here are some example questions I found from Pew Research:
• How much thought have you given to the coming presidential election?
• How closely have you been following news about the candidates?
• Do you plan to vote in the presidential election? How certain are you that you will vote?
• Rate your chance of voting in November on a scale of 10 to 1, with 10 being “definitely will vote” and 1 “definitely will not vote.”
• How often do you follow what’s going on in government and public affairs?
• Have you ever voted in your precinct or election district?
• How often would you say you vote?
• Do you happen to know where people in your neighborhood go to vote?
• In the last election, did things come up that kept you from voting or did you vote?
