To quote a line from the film "Cats and Dogs"
NOT GOOD!!!
The rules of engagement of opperation "Pay Back", the voting should be such that harm is minimised. Usually this means that the one suffering most will be exited.
In the beginning this was seen as Alex, due to his stressing out about hygene. Alex has managed to improve, especially now the influence of Sandy is gone.
Spencer Is not suffering that much, even though he is on the wrong side of those wretched bars (Sorry wonderful bars - We must not disagree with the focus group)
Looking at a wider picture, brings me to Kate. As far as I can tell Kate has formed a bond with Spencer. His removal could therefore cause some pychological trauma on Kate and break her heart (sorry sick bags are provided in the seat in front

)
Therefore from a harm minimisation principal, Alex needs to leave, so Spencer can stay
However I do not think this will happen due to the strong "Keep Alex" in campaign run by RI:SE