Charles Krauthammer has an interesting piece on why George Bush's second term is unique in recent presidential history and why Bush has an opportunity to be among the most consequential presidents ever. The gist of it is here:
There is an unusual feature to the second Bush Administration that is extraordinarily important but has been almost entirely overlooked. For the first time in a half-century, a two-term presidency will end without sending out its Vice President to seek a mandate for succession at the next election. Vice President Cheney will not run for the presidency, and everyone knows it. When these eight years are over, the Bush-Cheney Administration will simply close up shop.
[T]he fact that Bush-Cheneyism will never have to seek popular ratification again gives Bush unique freedom of action. Which, in the hands of a President with unusually ambitious goals, will yield perhaps the most energetic - to some, the most dangerous - presidency of our lifetime. Bush is fully aware of his situation. Hence the remarkable alacrity with which, after the election, he seized the moment. No two-month vacation to unwind. No waiting for the January Inauguration to set the agenda. He waited but two days to lay claim not just to victory but to a mandate.
Then, even more audacity. He not only claimed his mandate. He defined it right on the spot. Seizing the third rail of American politics, he promised to reform Social Security with, at minimum, partial privatization. He then added his intention to radically redo the tax code - which includes entertaining such ideas as entirely abolishing the Internal Revenue Service by going to a national sales tax. You cannot get more radical than that. His subsidiary aims, earthshaking in any other context but almost minor in this one, are kneecapping the lawsuit industry with serious tort reform and installing a conservative judiciary that will long outlive his presidency.
[T]he President is taking control of his government. In a country where the bureaucracy is so entrenched that the government is often at war with itself, that is revolutionary. As is the man in charge. Bush is marshaling his forces for the single-minded pursuit of a foreign policy rooted in a radical idea: the spread of democracy, particularly in the Middle East. That means unrelenting pursuit of the war on terrorism and no flinching on Iraq. Those who thought a re-elected Bush might reverse course and seek an exit strategy have been sobered by everything that has happened since Election Day.
This sounds like the next four years will be fun to watch, unless you're a Democrat - or an Islamist.