Larry:  It's a fairly old story, which is probably why it isn't currently being reported.  Beckel made that comment in a Fox news interview in 2010 - around the time wikileaks was publishing State Department cables leaked by Bradley Manning.  Contrary to your assertion, he was not then (and apparently isn't now) a "Clinton strategist".  From the context of his remarks it appears he was saying that the U.S. government ought to illegally assassinate Assange, not that some random gunman ought to off him.  Personally I think it was a highly irresponsible remark on his part, but in case you have some difficulty parsing the difference, Beckel was a talking head TV commentator (who subsequently went to work for Fox news) who spouted off something irresponsible, while Trump is a mainstream party presidential candidate who routinely spouts off irresponsible comments in his campaign rallies.  So there is that to keep in mind.