Those of us "in the know" remember VP Biden visiting the D.R. in 2014.
Those of us who really know... know that VP Hubert Humphrey visited the D.R. in '66.
NY Governor, Nelson Rockefeller, visited in 1969, 4 years after the invasion and, thus, the chant (and accompanying graffiti), "Fuera yanquis de Quisqueya," was still resonating all over the land. With such recent history, Rockefeller was not received with open arms by the populace.
The U.S. Embassy went on red alert, and urged American citizens to stay home.
BONUS tidbit: VP Bush in '81.
Ho Chi Minh visited the D.R. while working as a merchant mariner.
There you have it.