The Constitution does not recognize "tickets", "running mates", or any other such nonsense.
Biden was nominated by the 2008 Democratic National Convention, not by Obama. The Electors for Vice-President of the United States are chosen as the Legislatures of the 50 states direct, and, all 50 states recognize these national nominating conventions as valid for the purpose of chusing Electors.
Mr. iden is absolutely, unquestionably the legal and valid Vice-President of the United States.
It's only a matter of time before these cranks start claiming that Biden was born in Kenya.