You ascribe a little too much malice, forethought, and cooperation than the US government is responsible for (or capable of for that matter) in this case.
The matter isn't all that complex. Democrats recently came to power in the House and Senate. Democrats like all of that human rights garbage, some districts do have sizable Armenian minorities, and they simply tried to pass a symbolic bill.
The Bush Administration explained how such an act would be damaging to US/Turkey relations at a time when we need their cooperation and convinced enough people to give up the effort. That's all there is to it. No political ploy. No conspiracy. Just Democrats trying to recognize a human rights atrocity, the president appealing to present day national interests, and the matter discarded without a vote.
Noone cared enough about the issue to actually fight it out. And when it was clear that it would hurt our interests and that there would be a fight if pursued, it was put on a permanent backburner.