https://fivethirtyeight.com/features/the-states-where-democrats-are-overperforming-most-and-least-in-special-elections/ - as of March.

One pattern that should worry Republicans is that Democrats appear to be running farthest ahead of their presidential candidates in red states. The top nine states on the list all voted for Trump in 2016, while eight of the bottom 12 voted for Clinton. That suggests that Democrats are indeed doing better in the conservative areas where they need to make 2018 inroads.8 Specifically, special election results suggest that the white-working-class-heavy Midwest — which broke heavily for Trump in 2016 — may not be lost for Democrats after all. Democrats’ 26.2-point overperformance in Iowa, for instance, may help Democrats pick off two House seats they would probably need for the House majority.

And, as I mentioned, Democrats will have to defend several Senate seats in ruby-red states to have any chance of winning that chamber; these numbers should give them hope. The 21-point Democratic overperformance in Missouri, for example, should bolster the confidence of Sen. Claire McCaskill, one of the Democrats’ most endangered Senate incumbents.


All the actual election results I've seen (as opposed to the recent opinion poll) thus far show this trend continuing.

Will making it happen in November be a sure thing, or an easy thing? No. Am I often too optimistic? Yes. But I'm not as pessimistic as many here.

YMMV.

Cheers,
Scott.