Biden is impeachment insurance.
no because if Obama loses the electoral votes from CA for instance because of the lawsuit. Then McCain is president.
It would not be impeacment.
Obama has enough electoral votes that he could lose California’s and still win. If he was declared ineligible, the Democrat electors would still cast votes, so they would have to pick someone else, but it wouldn’t be McCain. If they didn’t agree and no one person had a majority of electoral votes, the House of Represntatives would choose the next President from among the top three, which would include McCain since there’s no way the Democrat votes could be split three ways and have 3 people with more votes than McCain.