Here's one argument for McCain that I hadn't thought of:
A president's pension currently is $191,300 per year, until he is 80 years old. Assuming the next president lives to age 80..... Sen. McCain would receive ZERO pension as he would reach 80 at the end of two terms as president. Sen. Obama would be retired for 26 years after two terms and would receive $4,973,800 in pension.Therefore it would certainly make economic sense to elect McCain in November.
However, I'm dubious that the President's pension cuts off at 80. What other pension does that? I'd have to have that proved.