Welcome to the Daily Kos Elections 2018 midterm liveblog! The first polls have now closed in the portions of Indiana and Kentucky in the Eastern time zone, though while we might see a trickle of votes soon, it'll be a while before we have meaningful results to chew on.
In the meantime, there are three important things to keep in mind:
1) The early vote may not look like the Election Day vote. In many states, especially those where a substantial portion of ballots are cast early, the first results you see reported will be those early votes. (In fact, early in the night, you'll often see a sizable chunk of votes tallied even though results sites say "0% of precincts reporting," because those precinct counts only refer to votes reported on Election Day by actual, in-person polling places.)
Here's the most important thing, though: If, say, Democrats in a particular state were amped up and decided to vote early in disproportionate numbers (or if organizers were simply better at getting Democrats to vote early), then Republican vote margins could improve as Election Day votes are toted up—or vice-versa. This is entirely normal, and just something to be prepared for.
2) Exit polls can be very misleading. For one, exit polls are continually updated throughout the night, as exit pollsters add additional "waves" of interviews. For another, like any other poll, they can simply be wrong. Also, this year, for the first time, we'll have two competing sets of exit polls from different consortia. It's hard to be patient on a night like this one, but it really is best to wait for actual results.
3) We might not know who wins the House tonight. In a number of states with large numbers of mail ballots, many of those votes are not tallied until after Election Day. That includes California, which has as many as 10 potentially competitive House races on tap, as well as Arizona and Washington, which also have several. While we of course hope to know the ultimate outcome tonight, we could be waiting quite a while: In 2016, the race in California's super-close 49th District wasn't called for three weeks.
Before long, the results will be flowing hot and heavy, though, so just stay tuned and we'll keep you fully up to date!