there was a FACE of the movement, that being MLK who had considerable clout but he didn't make decisions by himself and there were always various groups within the CRM that had diff ideas/goals. sometimes they agreed sometimes they didn't. SNCC being one obvious example, the MFDP being another. So when they say there isn't a leader of the CRM they are saying there isn't just one person who you can hang your hat on and say he is the leader/he makes the decisions the way ppl did/have done with MLK.