Regardless of who you vote for, change is most certainly in store following the 2008. And it may not be the change you think or what the candidates are campaigning for in the future.
A look at U.S. political history shows a cycle of power shifting back and forth between the executive and legislative branches. The executive branch has dominated the federal government since FDR and the legislative branch has slowly lost more and more power. Perhaps now, more than any other time in U.S. history, the office of the president is as strong as ever. (By the way, the judicial branch has steadily increased it's power since 1789.)
Regardless of who serves next as our president, Congress will almost certainly grasp power back. How much power depends on who wins and how you like your salsa.
Mild: Obama
Medium: McCain
Hot: Barr
Muy Caliente: Nader
Obama is almost certainly destined to be a the weakest executive of the four. With little federal service and even less executive experience, Obama will take about two years to learn the ropes. That will give the first Congress to serve with him time to take action. And with a platform promoting so much change, very little can actually be done. The world is naturally change adverse. By the start of the third year, Obama will have become a deal maker with Congress, and Congress will capitalize.
McCain's lack of executive experience will be initially offset by his many years in the Senate. He will be apt to work with Congress and just that act alone will cede power back to the legislature. His policies would require less changes from the status quo. Still, the Congress will likely see the chance to seize more control.
Of course, either candidate will be coming from the Senate. Naturally, they might favor legislative tendencies.
Barr would keep things very much the same as they are today. But increasing displeasure in the status quo would allow the Congress to finally take action to turn the ship. Barr would thus begin to lose power, but still hold on to much of it.
Nader...well, who knows really? He's been more of a lobbyist and crusader in the past 4 decades than anything else. There really is no telling what kind of government man he would be. His stubbornness on policy, though, would likely lead to Congress taking more action. But it remains a mystery.
A vote for Barr or Nader, too, is a vote for a different kind of ideology as well - one that fights against the ills of a two-party system.
Whichever way the election goes, I think the next president will only serve one term. The person elected will likely be ineffective for most of his term. Unless he can gain serious momentum into the 2012 election, it will be a new kid on the block, one who will likely set the stage for the presidency in the 21st century.
