He was #2 of those running for the position. He may have been running as a lackey but his name is on the paperwork.
It could be any 35 yo natural born citizen. The Constitution is clear that the Electors are assumed to be wise, and their word is law, unless they do not agree by majority on a single person.The Constitution does not even specify that there be a popular election for POTUS. At all. Your state has the right to, for example, pick Electors by lot.
Chelsea is old enough...the Democrats could just do it the North Korean way, keeping it in the family.