I am a bit more pragmatic than LS. Historically, mid-term elections have been a tough sell for the party of a newly elected POTUS. The other side is eager to get some semblance of power back and is motivated. Thus, the advantage to begin with has been with the democrats.
Having said that, it seems to me that the Dems sure have done everything in their power to squander that advantage, if not outright eliminate it. They made the ultimate unforced error in failing to put forth an agenda and placed a Kavanaugh cherry on top. On the other side of the ledger, the President has worked his arse off to motivate our voters. Let us hope that the actual GOTV apparatus has been there to convert GOP enthusiasm to actual votes.
It would defy common sense for the Democrats to do well, they have no vision, they have no leadership except for corrupt, stale old retreads, and they seem to be content to be tagged with a pro-caravan image that they could easily have shaken off if they had chosen to do so.
I feel optimistic (as a supporter who does not live or vote in the USA) in part because I have a feeling that Trump is making inroads into their base of support at least among male voters who really may be a second wave of blue democrats following the Midwest surge of 2016.
Despite the obvious signs that stupidity is too entrenched to overcome in the cities, I look for a few upsets here and there to keep the House marginally Republican. Senate seems like a solid win.
“Historically, mid-term elections have been a tough sell for the party of a newly elected POTUS.”
personally, i think the reason for that is that two years has been enough time to reveal that the new POTUS is nothing but a liar, failed to keep a single campaign promise, and often actually reverses himself and repudiates some of those promises ... Trump is the first POTUS in my lifetime that made that many promises and kept them ...