POLITICAL PARTIES ARE NOT GOVERNMENTAL ENTITIES

There is a discussion about what happens if a candidate for president dies, drops out, or is replaced before election day. Many people would like us to believe that this is a matter of constitutional law or even a law passed by congress.
Political parties are not governed by the Constitution nor laws. Political parties are private non-governmental entities. A presidential candidate does not have to be a member of a political party. The political party establishes its own rules. It is not a law that a political party uses a specific method to nominate its candidates.
If Biden drops out as a candidate before the nominating convention, the Democrat party will have to determine how they choose their candidate. If Biden is force out after the Democrat convention, the Democrat party will have to determine how they replace him.
The winner of the general election is not officially elected until the electoral college declares who is the president-elect. Despite what the Democrats are telling us today, electors can be challenged and have been many times.
The Constitution does explain how an individual, not the nominee of a political party, is elected to the office of the president. The election of 1796 marked the emergence of the political party system in the United States. In the previous elections of 1789 and 1792, George Washington won unanimous support with no party affiliation.
When asking what happens if a candidate for president dies, drips out, or is replaced before election day, you must ask the political party. The solution could be the same for both political parties, and it could be different. Political parties are not mentioned, perhaps not even contemplated, by the Constitution.