The power of the right comes not from popular support and media spin, albeit such support and spin are an important component of it, but from objective conditions that altered the economic playing field and the fact that the right managed to came up with some prescriptions (poisonous, but prescriptions nonetheless), whereas the Left was either ranting about the past or altogether sleeping with its hand in the chamber pot, as they used to say it in the old country in the Solidarnosc era.
Therefore, while Katrina inflicted some visible damage to the image of Bush admin, it inflicted no damage to its power basis. So it seems that it is liberal and fellow travelers who are dreaming.
To be specific, liberals came with some good proposals of using reconstruction funds to restructure land use and zoning that created concentrations of poverty in the first place http://www.npr.org/templates/story/story.php?storyId=4846580 but these proposals are mere shopping list of some nice things that can be done, but they do not provide an alternative to the right-wing or neo-liberal weltanschauung that captured public imagination.
Stated differently, the liberal response should be "Katrina shows the bankruptcy of the entire political philosophy based on small government, self-regulating market, individualism and cutting of public services. Here is an alternative philosophy that solves all the concerns raised by the right (economic efficiency, global competition, national security, personal responsibility) but goes much further by addressing issues that the other philosophy does not (social justice, democratic governance, equal opportunity, quality of life).
I am yet to hear such a response from the left.
Wojtek