The Republican Party is pathetic but I don’t believe this for a minute. There are very few swing Congressional seats these days, and the Democratic margin of victory in swing districts does not vote in midterm elections. Add to that a booming economy and Trump winning in the Middle East and I just don’t see a Democratic wave.
Dem turnout is way up in the past year. They’ve been flipping deep red seats (state house races) where trump won huge margins.