It's not that complicated

Jon Chait seems genuinely puzzled about how conservatives are able to maintain seemingly contradictory views on taxes and deficits:

The Republican Party is thus able to simultaneously believe that debt financed tax cuts always succeed in leading to spending cuts, and that Bush's policy of debt-financed tax cuts failed because it was accompanied by higher spending. It's one of the cult-like attributes of conservative movement thought.

I don't think it's a cult-like attribute, it is the natural result of what happens when one tries to maintain a position of "fiscal responsibility" when in fact the true agenda is keeping taxes on the wealthy as low as possible, deficits be damned.