The CIA expected there would be demonstrations over the partition when JFK touched down in Ireland almost 50 years ago.
Prior to his Irish visit the first Catholic Irish American president had spoken about his support for a United Ireland. As a young Massachusetts senator in 1952 he maintained it was "vital to the prestige and influence of the United States to be placed firmly on the side of a united Ireland, and that is our cause, that is our right and for that I am going to work."
The Irish Independent reports that ahead of the 1963 visit, Irish Minister for External Affairs, Frank Aiken suggested to the American Secretary of State, Dean Rusk, that Kennedy "might take some appropriate opportunity of urging on the British that they should indicate publicly that a solution of the partition question is desirable."
However Kennedy was anxious to avoid the delicate issue but did refer to Irish independence during his address to the Irish parliament.
“No people ever believed more deeply in the cause of Irish freedom than the people of the United States.”
“I am deeply honored to be your guest in a Free Parliament in a free Ireland. If this nation had achieved its present political and economic stature a century or so ago, my great grandfather might never have left New Ross, and I might, if fortunate, be sitting down there with you,” JFK said during his speech.
No large scale demonstrations did occur and a New York Times article suggested that most people who came out to greet Kennedy during his Irish tour were "willing to forget that the six northern counties are still under British rule."
Here's the audio of JFK's speech to Ireland's parliament: