This one confuses me. The first clue implies a person as the answer, but "What am I?" seems to imply otherwise.
Teddy Roosevelt became president when McKinley was assassinated, but any president after him would also fit the first clue. On the other hand, no president was a basketball star. I think I've heard of Bill Withers, but I don't know any of his songs. From the Olympics clues, I'm tempted to guess "running shoes."
George