1. Here's a good overview of the mix of early vote and demographic data that seems to show things moving in Clinton's direction in Florida. I say seems because there are so many moving parts and variables that there's no way to make a direct apples to apples comparison between 2012 and 2016 and see who's doing better. What seems pretty clear is that the partisan and demographic profile of the early vote is better for the Democrats than it was a week ago. And it seems to point to a narrow Clinton victory. Emphasis on the seems. (This Times article that just came out cover more than Florida but also includes important information.)
2: What if the electorate isn't as diverse or young as we think? Well, it isn't. Or at least there are pretty good arguments that the exit polls, which people often discuss as something as concrete as the vote itself, is not quite accurate. Not dramatically off but a bit off and off in the direction of a whiter and older electorate. Here's an article by Nate Cohn in The Upshot from June that explains it. Now, this doesn't mean our demographic and predictive world is turned upside down. Trumpite Republicans frequently talk about a 'hidden' white vote. This would suggest that there is a hidden white vote - only it's made up mainly of people who voted for Obama. The one thing it does suggest however is that those who say that the GOP has basically maxed out the white vote may be a bit off. Their may be more room for growth than the exits suggest. Again, the broad story about the Obama coalition, an increasingly diverse electorate is clearly right. There's just data that suggests me may not be quite as far down that path as a lot of us assume.
3: We've seen and discussed this pattern again and again. But we're closing the race on it. Clinton is seeing surprising strength in former Democratic 'reach' states, largely driven by minority and especially Hispanic voters. At the same time she's seeing relative softness in much whiter states in the northern tier of the country which have seemed pretty solidly blue for a generation. My best guess, looking at all the numbers and number crunchers at my disposal, is that she wins the Northern states anyway, with perhaps slightly lower margins and picks up states in the South and West. But this is going to be one of the big closing questions of the election - just how and how evenly is that shift in the electorate spread out over these different regions.
4: Even more than it seemed yesterday, Democrats seem to have built up a close to insurmountable lead in Nevada. If it's tight on Tuesday night that could be a big deal.