Actually, Objectivism's political approach is a subset OF libertarianism. Objectivists are libertarians, no matter how much they stomp their feet and whine otherwise. Objectivist libertarians certainly have a philosophical foundation for their adherence to NAP -- as do many non-Objectivist libertarians, although that foundation may be a different one.

Many non-Objectivist libertarians have the same philosophical foundations for their acceptance of the NAP as Objectivist libertarians do -- but apply Ayn Rand's principles more soundly than Rand herself, and especially Rand's heirs at the Ayn Rand Institute, have applied them.

[swiped from RRND holoscan comment system. --MJ]