I may be off by a week or two, but I said this back in August:
As for the House this year, it's really too early to say. I agree with most people that say that it would take a wave (i.e. anywhere from a solid Clinton win to a landslide) for Democrats to win back the House. That cake isn't even done mixing, let alone ready to bake. I don't think we'll know the true House landscape until after the first debate. Waves really tend to materialize in October. I think there will be races not on the radar that will be if we're at this point in late September (which basically has to happen if a Democratic takeover is to actually happen). Split-ticket is sure to increase this year, but if Trump is losing suburban Republican-held seats by 15 or even 20-points or more, very few will survive. No gerrymander will protect against a 40-point or even a 2-1 Hillary win in the Philly suburbs (which is the current polling). I think it's general political conventional wisdom with gerrymanders that the bigger they are, the harder they can fall. I think it will take a sizable win for the House to fall, but it is a significant possibility that cannot be ignored.
To answer the questions, let's wait a couple days and see what's what. I think it's very possible that it is though. The way Republicans are running from Trump leads me to believe that there is some very nasty internal polling. I know the Washington Establishment has never been particularly enamoured by Trump, but I think it's virtually unprecedented to abandon the top of the ticket as many Republicans are doing now.
It's also worth noting that Stu Rothenberg retweeted Sean Trende saying the House is in play.
