In the short story That'll Be the Day by Jack C. Haldeman and Barbara Delaplace in the alternate history novel Alternate Tyrants by Mike Resnick, an amendment to the US constitution lowers the voting age and America's youth elects Elvis Presley for president.
In the short story "Ike at the Mike" by Howard Waldrop, jazz singer Dwight D. Eisenhower is jamming with president Elvis Presley, who used to dabble in music when he was young.