For 4 years, the Democrats have been indignantly dumbfounded by how Donald Trump ever got elected. They chose to explain it to themselves by denigrating half the American electorate as ignorant, racist, deplorables. They did not, and still do not realize that it is precisely this attitude of theirs — towards the working class, towards middle America, towards small business owners, towards Christians — that got Trump elected.
If Biden is confirmed as the 46th President, this will ensure that they will never understand what happened, and will never change. If you are a Democrat, this should concern you. If you are a Republican, this should give you considerable assurance.