I was thinking over that question last night as I fell asleep at the Army War College, where I am visiting. I think one reason President Obama excites so much emotion is that he represents the end of the Reagan revolution.
Look at this way. FDR's New Deal lasted about four decades, until it began collapsing under President Carter. Then Reagan came along. In a nutshell, he inverted the New Deal: Government was not the answer, he said, it was part of the problem. He also began a massive transfer of wealth from the middle classes to the top 1 percent of our society. One reason he could do this is that he didn't get us into an expensive war.
In both cases, eventual successors from the other party lived with the work of their predecessors. Just as Eisenhower did not try to undo the New Deal, Clinton did not try to reverse the Reagan revolution.
I don't think Obama killed the Regan revolution. I think it was getting old -- it had lasted nearly three decades. But I think the Reagan influence effectively was killed by President Bush's lengthy Iraq war, which proved so expensive that it was no longer possible to transfer wealth to the rich at the Reagan-era rate without running up huge deficits.
Obama, I think, buried the corpse, especially with his second inaugural. Government, he is saying, often is part of the answer. I think people are ready to hear this. They don't mind paying taxes as long as they believe the results are concrete: fewer potholes, longer library hours, healthier kids -- and disaster relief for the victims of Sandy.