Baker v. Carr didn't even deal with one-man-one-vote per se. It dealt with who gets to draw district lines. Historically, that was (and still is) done by state legislatures. Prior to the Warren Court, the Political Question Doctrine (that's a doctrine saying that the Supreme Court should stay out of stuff that the legislatures should be dealing with) kept the judiciary out of the issue.
Either side of this particular issue is actually tenable; someone has to draw those lines, and it might be a good idea to have the courts as a backup in the case of gerrymandering. But Biden mischaracterized the living breathing hell out of what Alito's position was. Alito said that the courts should simply stay out of it, because an abusive court can be just as dangerous, if not more so, than an abusive legislature.
Biden translates this to mean opposition to the principle of one man, one vote.
I have been trying to learn Alito's actual view on the duplicate thread, but so far I haven't been able to figure it out. Could you be more specific as to why Alito would be against equal apportionment? Is there a case, or other writing that makes his view known?
It would be good for the country to have this whole idea of one-man, one-vote rehashed in the Senate. It has always been an incomplete idea, because without a flat tax, one man one vote is a license for democracies to redistribute wealth. The poor will always outnumber the rich, but they both have equal property rights. It should be one man, one vote, one tax. If we have flat representation, i.e. one man one vote, we should have flat taxation, not progressive taxation.
The 16th Amendment/nightmare actually says "...and without regard to any census or enumeration". I can't believe what has been done to our Constitution. We have progressive taxation, with flat representation.