Who is the easiest?

Five surgeons are out to lunch together, and discussing who makes the best
patients.

The first surgeon says "I prefer to have accountants on my operating table.
When you open them up, everything inside is numbered."

The second surgeon responds " Yes, but electricians are easier to operate
on.  Everything inside them is color coded."

The third surgeon counters with "No, I really think librarians are the best:
everything inside them is in alphabetical order."

The fourth surgeon chimes in: "You know I really prefer construction
workers... they always understand when you have a few parts left over at the
end, and when the job takes twice as long as you predicted."

But the fifth surgeon had the final word: You're all wrong. Politicians are 
the easiest to operate on.  There's no guts, no heart, and no spine. And the
head and butt are interchangeable."