Most of America are sick of Trumps act, that's not a left or right thing. There was a congressional and state and local elections and despite Trump being beat by what I would call an awful Democrat candidate by a decent margin in popular vote Republicans won across the board. As for special elections one thing to keep in mind Trump as a political amateur might not have picked the safest nominees in terms of replacing them. Trend lines look good for Democrats in these limited one at a time well funded races, and if you look at the tea party example that looks like a big deal, but enough to flip congress still seems like as long of a shot as the Republicans padding the lead. Don't confuse anti-Trump with pro democrat.