Expat Voting Patterns in US Elections

[pantom]

I’m fond of the site the Electoral Vote Predictor; I check it every day to see how the state polls say the electoral vote will swing.
Today (Sept 13) the site asks an interesting question, phrased thusly:

I have it on good authority that overseas voters are registering in huge numbers this time, maybe double or triple 2000. I was told that the number of people who showed up at the Democratic party caucus in England earlier this year was 10 times what it was in 2000, ditto in other countries. Americans overseas vote in the state they last lived in, even if that was decades ago. There are about 7 million overseas Americans and probably about 5 million are over 18. In Florida, it was the overseas absentee ballots that swung the election. I believe that something like 8% are military, but the rest are students, teachers, artists, government workers, business executives, spouses of foreign nationals, missionaries, retirees, and more. What is significant here is that these people represent a lot of votes and are not included in any of the polls. Nobody knows if they are largely Democrats or Republicans, but their votes could be one of the big surprises of this election. if anyone has any actual data (as opposed to speculation) on this group, I’d be interested.

Seems to me this is an excellent question. Anyone out there have any answers? This is strictly for my curiousity, although I’ll send him a link in the mail if this thread comes up with some good answers. (please keep partisan stuff out; despite being a rather, um, enthusiastic participant in GD, I’m looking strictly for data. Also, I have zero connection to this site. Haven’t even so much as written an email to the guy.)