The regress argument is also termed 'the problem of criterion' or 'the diallelus'.
The argument refers to a problem in epistemology and, in general, in justification of any proposition or explanation. According to the argument from regress, any and all propositions require justifications, which themselves require support, since, it is assumed, nothing is true “just because”. Reaching the bottom of the regress brings the explanation to the the physical "just because" level.
"Bottom" is that ultimate, necessary condition for which there is no logical explanation, but which is merely the situation of inexplicable existence. This is what the just-God theists deride as being just-so. Necessary conditions describe the fundamental physical constants that underlie the nature of our cosmos: "All we currently know from fundamental physics and cosmology remains consistent with a universe that evolved by purely natural processes." (Stenger)
The problem with apologetic deistic arguments lies in their artificially moving the regression back one emotional level to a God for which there remains no explanation.
For reasons of emotion stemming from childhood indoctrination, theists and deists are not satisfied with actual necessary explanation. Instead they feel the need to regress back to a pseudoexplanation that they define as ineffable or inexplicable. They appear to feel that arguments from definition are valid while materialistic explanations require tu quoque "faith". Occam's razor dictates that adding such unecessary factors to an explanation is not acceptable. Scientists are realists who are capable of being satisfied with hitting physical 'bottom', deists and theists need more illusion of control over the metaphysics.
The NY Times posted an op-ed argument entitled Taking Science on Faith. The piece is by deistic Christian apologist Paul Davies, and illustrates the problem with fallacious argument from regress.