Constitutionality/Legal: Can a person be nominated for president by 2+ parties? With different VP? Lets say John Kasich wins the Republican nomination and selects, oh lets say Marco Rubio for Republican VP.

Could Trump decide to run as a 3rd party for vice-president (say, Libertarian Party) and convince them to also nominate Kasich for President.

1. Could Kasich accept the nomination from both parties?
2. If yes, how would the electoral college representative be selected if the sum of votes for Republican+Libertarian &gt; Democratic in a state, but neither is greater by itself?