I count 12 possible. And if we have a 1934 type year, it could be more. Essential to recruit the best electable candidates.In some states, that means 90%+ conservative. Others, 80, 70, 60, even 50%. And make the Dims campaign in every single state and district.
Trump won without maximum ground game. We now have a chance to also recruit more ground game. Every thing from precint committeeman/woman to Senators and Governors. Ohio has a governor’s race in 2018. What does your state have?
What makes this more interesting is that with 60 (after 2018), any vacancies in the Supreme court have an iron-clad passing rate. Count in the 2020 Census, and massive redistricting in five “red” states, and it’s simply paving a yellow-brick road.