Finally, if Democrats win the House in 2018 (which they have a good shot of doing)
Nitpick: that link shows Democrats with a just-under-8-point national lead. Both 538 and RCP consider an 8-9 point national lead to be the bare minimum Democrats need in order to break even in the House, taking gerrymandering into account. So that really shows Democrats gaining seats in the House but failing to win a majority, and of course that doesn’t take into account the voter suppression and Russian interference which we can safely assume will be much more aggressive this time around.