If Magic Johnson is even interested in running for the presidency he should run for governor of California first in 2018 than run for the presidency in 2024.
Last point ,I highly doubt Magic is interested in becoming any type of politician.
He is a good businessman, good public speaker. Very educated man.
That doesn't mean they would be interested in becoming governor or president.
Anyway if he wants to run for president he should run for governor first serve for at least 6 years then only should he run for president