It is more politically palatable for the liberals to maintain the primary cause is homosexuality because it is an ‘alternative lifestyle’ which allows them to blame government for not taking enough money from hard working Americans to fund ‘aids research’. Blaming the primary mode of transmission on needles isn’t politically defensible - yet. Just give Obama enough time. He’ll find a way to blame you and me for some poor black person sticking a dirty needle in their arm and getting aids...It WILL happen.
Even if he can't find a way to blame us for it, he'll find a way into our pockets to pay for "researching" it (which is dim speak for showing that you care even if it has absolutely no chance of doing a damn bit of good).