Defending the Constitution

I was thinking about the ongoing discussions as to whether Sarah Palin is qualified to be the President of the US should the need arise and re-read the Presidential Oath of Office as a reminder of what the job entails. The Oath reads as follows:

"I do solemnly swear (or affirm) that I will faithfully execute the office of President of the United States, and will to the best of my ability, preserve, protect, and defend the Constitution of the United States."

Judging by what I see and hear, the vast majority of people interpret the "protect and defend" clause in its most obvious sense, whereby we are threatened by a foreign military power. Clearly, this is a highly unlikely scenario. We are still the only remaining superpower. Our military budget equals the rest of the world's nations military budgets combined.
Loss of Constitutional power through other actions, however, is always a possibility. Internal power grabs or slow erosion may occur. Preserving the Constitution in this sense requires a deep knowledge of the Constitution itself, as well as a familiarity with Constitutional interpretation and the historical court cases developing that interpretation. In this sense, Barack Obama certainly has the most credentials. He has a JD from Harvard and taught Constitutional Law at the University of Chicago Law School for twelve years. Next would be Joe Biden, who earned a JD at the Syracuse University College of Law and has a long career in the Senate. Senator Biden currently chairs the Senate Judiciary Committee. Next is John McCain. His academic career at the Naval Academy was not directly related to law, but his long service in the House and Senate has clearly given him direct experience with the checks, balances, powers, and limitations laid out in the Constitution. Sarah Palin has none of this. She holds a Bachelor of Science in Communications-Journalism, two terms as the mayor of Wasilla, and is in her first term as the governor of Alaska. There is nothing in her resume indicating a sense of Constitutional Law, or issues that may arise. This unfamiliarity leaves her vulnerable to attack, and by extension, We The People are vulnerable if she is in office.
Sarah Palin has some good qualities. She's confident, articulate, intelligent, and aggressive. But, she doesn't have the training or experience to work within a Constitutional framework. Will she be able to protect Executive powers from a greedy Congress? Will she push back if her advisors attempt to push her further toward the Unitary Executive that George Bush's administration envisioned? I doubt she could gain that kind of insight in such a short time. Regardless of our political leanings, we should be able to agree that putting a Constitutional amateur in the White House is not the most likely way to ensure that the President can fulfill the Oath of Office.