Your challenge, should you choose to accept it, is to make Colin Powell President of the United States of America with a POD no earlier than January 1, 1989.
This can be achieved through presidential succession, though he must at least be elected Vice President first (replacing another VP without an election is acceptable).
Bonus if he is elected on his own right as a Republican and is reelected by at least a popular vote margin of not less than 10%.
Double bonus if he is elected President as an independent.