“We all must begin with something that exists as a ‘brute fact’”. (p. 97)
This is a concept called foundationalism which has already been addressed in post L 5.15. Loftus is right. Every person from every worldview accepts certain ideas as foundationally true, including naturalists. The question between the worldviews is why people accept certain beliefs as opposed to others. The non-theist position is inadequate and this forum has shown several reasons why this is the case. We know that non-theists cannot prove that God does not exist which means that the foundational beliefs they have chosen rest on nothing substantive.
As stated before, non-theists concoct the idea of a multiverse to attempt to support the conclusion that the universe does not need an explanation. Since, the universe (or multiverse) cannot itself be proved to be a brute fact, imagining an eternal chain of multiverses does not provide an acceptable foundational belief. Even if a world ensemble did exist, it still wouldn't answer the question of origins.