Now as far as the issue goes...
President Kennedy would not be welcomed in the dem party of today,I have no reason to believe there was anyone other then Oswald acting alone but if that wasn`t the case what does it matter today other then to fuel the obsession of some.
There will be no other answer as most alive and of age to participate would have died by now.
It is a bit pointless to keep the thing going as so many do.
Generally, the "big" commemoration of an event peaks at circa the 20th or 25th year--for example, D-Day celebrations in 1964. There were other commemorations after that, including 1984 and 1994, but they were lesser. Of course, Dwight Eisenhower, Bernard Montgomery, and a whole slew of other famous personalities were still around then, and participated.
I've noticed the Kennedy assassination carried on a little longer, after which it began winding down, probably having something to do with the decline and death of Jacqueline Kennedy about the same time. That yesterday was the 45th anniversary of the assassination was buried in the back pages of the
Omaha World-Herald, for example.
Incidentally, some might remember that famous news photograph of Lee Harvey Oswald being shot by Jack Ruby, with that one law-enforcement guy wearing a cowboy hat leaning back in startlement. That guy's still alive (he's 88 years old now), and there was a story about him in the newspapers.....in the back pages.