It's no different from the situation with Obama's father. What activities the dads were involved in before they fathered Presidential material is OF COURSE relevant.
The cruz response was that the dad just happened to be there and simply took a leaflet that Oswald was handing out.
It is very odd that a Castro supporter who was also imprisoned in Cuba at one point was allowed to travel to the US to live, and happened to be photographed with the man who assassinated JFK.
Obama dad 1: fought for Mau-Maus
Obama dad 2: was involved in ways unknown to us in Sukarno overthrow in Indonesia involved in Suharno and Sukarto (too much info to discuss here)
Obama dad(s): alcoholics
Obama mentor: communist, pornographer, homosexual
Obama grandparents: communists
Obama dad(s): deserted their families
Obama's family: dysfunctional family (just one example: brother lives in metal container the size of a phone booth)
Obama dad: Got Obama into Columbia and Harvard Law on what money?
Obama: born in another country
Obama: birth and school records sealed
Ted's dad: fought for Communists in Cuba
Ted's dad: travelled to/from Cuba to Texas raising money for Cuban communists (at a time when travel was, to say the least, highly restricted, and CIA would have controlled/been aware of all travel to/from Cuba Ted's dad: Cuba connections, and Texas connections---similar to those of Oswald's Ted's dad: alcoholic
Ted's dad: deserted his family
Ted's dad: got Ted in PRINCETON and HARVARD LAW on what money? (right at a time Ted's dad and mom's business went "bankrupt")
Ted: born in another country
Ted: birth records (and school records?) sealed
Ted's family: dysfunctional---Ted and wife have virtually never lived in the same home or even city or even state; Ted's older daughter acts afraid of him; Ted's wife found wandering on highway, apparently during nervous breakdown
These are just off the top of my head.