Tonight's Presidential debate in Nashville, Tennessee, had great importance for both Sen. Barack Obama (endorsed by TER) and Sen. John McCain, but more was at stake for Sen. McCain, who has been falling steadily behind Sen. Obama in national and state-by-state polls over the past few weeks.
While McCain scored some points, this was far from the victory that he needed. He will not have many more opportunities to make up the ground that he did not tonight.
If there is a major change in campaign dynamic, it likely will not come from the remaining debate - or from the candidates themselves. Such a change, if it is to come, will much more likely come from an external event. It could be argued that the dynamic changing event has already happened - the global financial meltdown.
Looking at debates historically, those debates that did have a significant effect are now increasingly distantly in the past. One can think of the 1960 Kennedy-Nixon debates, the 1976 Ford-Carter debates, and the 1980 Carter-Reagan debates as having changed the direction of those elections. Part of the reason we have not seen such trajectory-changing debates recently is the advent of the 24-hour news cycle and the role of the Internet. Voters have a greater and more constant volume of information available - it's harder for any particular debate or campaign event to have the kind of important effect that the 1960, 1976, and 1980 debates had.
It is thus perhaps unreasonable to expect much change from the remaining debate, which will be held a week from tomorrow at Hofstra University.