Biden has won. The Senate stays republican and the house is too close for the democrats to vote for anything too controversial or else their own people will not vote for it.
With this Biden becomes the new president during the worst economic crisis since the great depression. So first he has to get his team together, confirmation hearings and all the usual procedure. That will take until early summer, still corona moves on and the economy is bleeding. Biden is now the face of this and of course, will get more frustrated because the democrats don’t have the luxury of Obama's first term when they had both chambers. His approvals will drop and this will hurt Biden because he wants to be loved.
Meanwhile, he is getting older and the economy will take years to get better. He has no majority, so he must work together with the republicans which will make the left within his own party incredibly angry, so he will be under attack from them as well. AOC and others will bring up topics, he has no majority to vote for and maybe even in the house she will not get a majority for her plans, because several democrats are afraid, that they will get voted out in the midterms.
Biden will probably use executive orders like Obama / Trump to get things done, but the Scotus and others will stop some of it as well. Because of all of this and his age/ health, he will not get to a second term. So, it will be President Harris vs. the Republican candidate. And let us be honest, even if the media is in love with her, the democratic base or the general population is not. She never got a lot of votes during the primaries and she has the charisma of a wet f blanket.
The democrats were so laser-focused to get Trump out of office, they never had a long-term strategy. Harris is not Obama, not even close and the party can not rally behind her. She is a corporate candidate; she lacks the warmth and the empathy of Biden. There will be millions, like after Obama, who were left behind, and she has no answers for them. If the Republicans find somebody who has and also has the energy like Trump had, they will take back the white house after four years and that would really break the democrats. The left will take over completely and they don’t have a majority in the US (not even in California, as it was proven for example with proposition 16).