You're wrong about my rating on presidents. Rating all 0 would mean I rate them all equally and all completely useless and I don't. The same applies to the Dems and Reps.

Do I think the US is net positive in the world, or that the Dems and Reps are net positive? No. The calculus behind those judgements are way too long for a sub-comment the week before Christmas and end of year (very busy time for my company due to year end financials).

Suffice it to say that in the last 40 years the standard of living for the majority of the US has not improved. There is no better single metric for ranking a president - the head of the executive branch - than that. Similarly, since the US took over as the leader of western empire after WWI, the portion of the world directly or greatly controled by the western empire has not improved. The catastrophe of worldwide civilization ending global warming is a single metric we can use there.

Let's say 5+ means a net positive trend. Off the top of my head (don't quote me on this) I rank the Ds a 4/10 and Rs a 3/10, the net result is still downward.