Half-blood Voldemort, Half-blood(?) Snape.

[backstagemystic]

No: HPFGUIDX 126732


Whether or not Snape turns-out to be the HBP, if he's a half-blood
regardless (possible, as JKR would not state whether or not he was
pure-blood, only that, "...he's no muggle-born"), then that might
explain a possible appeal to his becoming a follower of Voldemort in
the first place.

Voldemort loathed his muggle father for abandoning him and his witch
mother.  

If Snape endured some similar situation with his own father and
mother, then he might have felt an instant connection to Voldemort via
those similar circumstances (especially if Voldemort manipulated
Snape's emotions along those lines).

BM

P.S.:  Speaking of "Half-blood Prince," it need not refer to actual
royalty..."prince" could be an endearing name one calls another, such
as a father calling his daughter his "little princess" (or a mother
calling her son her "little prince").