The clear shown majority showed through polls shows democrats winning. America is fed of with Trumps actions and his illegal bypassing of congress, and they are fed of with rising prices. His hypocritcal stances on war and prices are enraging america.

Simply saying that is hard to defend seats is not a good enough reason. Sure the senate may be harder to flip but it isn't uncommon between presidencies to see either the house or the senate flip. Democrats are also vying at usually politically republican states like Texas, and its extremely close even with some polls showing democrats in the lead. At the end of the day momentum does matter, and Democrats have it.

In a time of high emotions a lot of voters may not consider mapping points. A lot of voters espiecially the younger generation fed up with Trumps actions may not even take logistical factors into consideration, and just select the democratic ballot on voting day. Also if someone just "shrugs" that doens't mean they are just going to end up voting for the side they may assume will win, that is illogical.