[Alberta's Child]

One of the big flags I've seen in recent polls is the polls of early voters in some states. They show Trump or Clinton leading (depending on the state), but also include an "Undecided" or "Uncommitted" number of 5% or so.

That is bullsh!t by definition. Someone who has already cast a vote cannot be "undecided" or "uncommitted" anymore.

[jjotto]

You do understand that NO votes for a particular candidate have been so far counted?

Totals are being based on the shaky idea that registered members of a party are voting for that party’s nominee. In some cases, the ‘results’ are achieved by counting early ballots mailed or cast in certain demographic areas as exactly reflecting that demographic’s recent voting preferences. Such numbers are too imprecise to be useful info if the election is at all close.