Some of this is a legitimate response to the political process: Voters tend to elect presidents who seem to possess qualities and views they thought lacking in their predecessors. But some of it, and especially in the case of Barack Obama, seems to come from an adolescentlike confidence that everything done by those who came before is (insert your own generation’s expletive here).
We have seen this spectacularly in the dozen days since the June 12 Iranian election. Back in July 2007, Obama said that he would meet with Iranian President Mahmoud Ahmedinejad and other tyrants without preconditions. Grown-up squares like George W. Bush wouldn’t talk to these guys, so as the avatar of the generation of hope and change, Obama would. Obama figured he was cool enough to get the mullahs to agree to renounce nuclear weapons and all that hate stuff.
Obama has held to this ever since.