Menachem,
I know of no Mekor for the Chiluk you prsent. The term “Ahavas Yisrael” MEANS loving a Jew for no other reason other than he is a Jew. That which he is a Jew IS A REASON to love him. Ahavas Chinam, a term Chazal never used, to me implies that there is no reason to love him but you should anyway. I am not even sure what to do with that.