We're seeing the most visible opposition to raising the debt ceiling from Republicans and the Tea Party. Some few old-style conservatives may actually believe in fiscal responsibility, but movement conservatives - who have reflexively voted for increases under previous administrations - are now exploiting the issue to appease the Tea Party and to obstruct Obama.
For very different reasons, many voices in the Energy Depletion community are also very much against raising the debt limit. Briefly, they feel that increased spending can only be supported by continued growth, and that continued growth can't be supported now that we are past the peak of oil, and probably closer to the peak of natural gas and coal than most people realize.
