So, the basic process of this list: find what year a President or a Presidential nominee was first elected (or, if they never held an elected position, what position they did hold, with the exception of William Knowland at the beginning), go to the House/Senate/Gubernational elections for that year, and pick a random person who also won an election that year (whether they were first elected or re-elected that), and was still alive when the Presidential election occur, and who wasn't a future President or nominee.