Unfortunately, to change him now will only insure absolute defeat for the Dems. One fact that is being overlooked by everyone in the Media that is raising this hue and cry is that the way that the cmapaign finance laws are written means that any money that has gone into a PAC supporting Biden cannot be used by any other candidate so you will have gutted a new campaign straight out of the gate. Secondly, it will be too late to get that candidate on the ballot in all 50 states. Thirdly, the Dems do not have a candidate that can galvanize the voters and win the election.

The real problem that this country has is a structural one as a result of the way the Senate is constituted. By having two Senators from each State that means that there is now permanent minority rule by the conservatives. If the Senate had proportional representation like the House none of these conservative justices could ever have been appointed to the supreme court. The Republicans saw what judicial activism did for the Democrats back in the 60s and decided to do the same. It is impossible to impeach and remove them as that would take 60 votes in the Senate and that will never happen.

Even James Madison foresaw that giving the smaller States equal representation in the Senate would ensure that a minority could always block the will of the majority. One possible solution would be to grant statehood to DC, Puerto Rico and the American Pacific territories or maybe to break up a State like California to redress the balance. At the moment we are stuck with this situation.

As to the Presidential election, whatever Biden's problems we just have to hope that in November enough people have enough sense that no matter what the choice that they do not pull the lever for a convicted criminal, adjudicated rapist, malignant narcissist who cares nothing for anything except himself and his ability to continue his criminality.