What if RFK actually is elected POTUS in 1968?
The first thing I can mention is immediate withdrawal from Vietnam starting in 1969 and being much faster than Nixon's. American forces are out by 1970's end. A ceasefire will be reached and South Vietnam probably collapses sooner by 1973.
I see the antiwar movement coming to an end sooner and racial tensions decreasing with minimal rioting.
No Watergate, bombing of Laos, or even reopening of China in 1971.