History tells us we can expect 38-40% turnout for the upcoming mid-term election. For both parties combined. That accounts for all the GOTV efforts we can reasonably expect. It does not necessarily account for ever-increasing voter suppression, founded firmly upon two rounds of the most egregious gerrymandering imaginable.
I see nothing on the horizon to alter the coming results. All the horserace tracking is focused on what is mostly predictable. No doubt there will be a few upsets, but basically everyone sees the Senate balance being a nailbiter and the Congress firmly in the grasp of the Republicans.
No one is proposing anything to radically upset expected outcomes, which are all based on traditional approaches to elections.