It's naive to think the US is a democracy. It's mostly an oligarchy with a few democratic features. The only choice is to vote Harris, but she is only barely less right-wing than Trump, from a European perspective. She will continue the oligarchy.
The only hope there is, is that all the people in the US start to understand they don't have a democracy. The vote for D needs to become overwhelming. Then, R will die out and an alternative choice on the further left side may emerge as a serious contender. Then, this further left choice needs to become overwhelming.
Eventually, this will lead to real change.
Why this must work like this is because the US' democratic system only supports 2 parties with its first-past-the-post system. Until a reform of this voting system takes place, towards a ranked choice style system, there can't be good representation. While any organization into a limited number of parties inherently means that almost no one will be represented perfectly, the less parties there are, the more the average divergence of reprentation there will be. 2 is just an unbelievably small number of opinion groupings to choose from, much too little to get anywhere near good representation.