The rationale behind social capitalism is that if you're born rich (or whatever), it doesn't mean you're the person most capable of maximizing your opportunities and hence providing the most profit for the society at large. Conversely, if you're poor (or whatever), it doesn't mean you're stupid.
That latter point gets lost on most people.
Even if we give everyone an education, people will differ in intelligence, and hence differ in opportunity. Therefore the public schools must aim to hamper the excellent. Why do they have the right to be clever at the cost of the stupid? Equality! Equality! Equality!
SocialCapitalism is an attempt to implement the TheoryOfSecondBest.
[Originally from Wiki:SocialCapitalism]
See also BoomerangEffect, BackDoorProtectionism, CorporateGovernment, SocialWelfare, YuppieSocialism, EatSushi, CapitalNetwork
The term social market economy might be useful.