An obvious negotiating tactic: draw a line in the sand and say, "It's this or nothing. Final offer."

If it passes it will be hailed as a great victory for the regime. 

But the Senate will have even more difficulty passing the bill and will likely end up amending it. Perhaps the real plan is to get the house to pass the 'hard' version, then the Senate waters it down, then the house ends up reluctantly agreeing to the watered-down version.