Of all the differences between the two major party tickets for the US presidency, one of the most profound may be their disagreement on the limits on the authority that the Constitution grants to the Vice President. That difference emerged in bold relief during last week's vice-presidential debate when Gov. Sarah Palin said:

I’m thankful the Constitution would allow a bit more authority given to the vice president if that vice president so chose to exert it in working with the Senate
and making sure that we are supportive of the president’s policies and
making sure too that our president understands what our strengths are. 

Palin's remarks ignited the blogosphere, with law professors and lay people lining up to either to attack Palin's understanding of the Constitution, or to denounce her critics. I'm no constitutional scholar, but as a citizen, I think this question is too important to be left to the experts. It's especially when the current vice-president has wielded extraordinary power, while declaring himself exempt from government rules imposed on members of the executive branch. 

The responsibilities of the Vice President are enumerated in the first two articles of the US Constitution, as well as the 25th Amendment. Article I designates the VP as president of the Senate with no voting power, except in a tie. Article II states that the vice president will become president in the event of the death or removal of the president. The 25th Amendment gives the vice president the power to serve as acting president if the president is incapacitated.  Beyond that, the vice president has whatever responsibilities the president asks him or her to assume. 

That's why some bloggers were mystified by Palin's remarks. BlogHer CE Catherine Morgan wondered:

Do you think the role of the vice president needs to be expanded even more than Cheney has already expanded it?  Wouldn’t that make the actual “presidency” irrelevant?

Todd Zywicki a the Volokh Conspiracy says it's actually Joe Biden who is confused about the proper role of the the vice president whe he said:

BIDEN: Vice President Cheney has been the most dangerous vice president we've had probably in American history. The
idea he doesn't realize that Article I of the Constitution defines the
role of the vice president of the United States, that's the Executive
Branch. He works in the Executive Branch. He should understand that.
Everyone should understand that.

And the primary role of the vice president of the United States of
America is to support the president of the United States of America,
give that president his or her best judgment when sought, and as vice
president, to preside over the Senate, only in a time when in fact
there's a tie vote. The Constitution is explicit.

The only authority the vice president has from the legislative standpoint is the vote, only when there is a tie vote. He
has no authority relative to the Congress. The idea he's part of the
Legislative Branch is a bizarre notion invented by Cheney to aggrandize
the power of a unitary executive and look where it has gotten us. It
has been very dangerous.

Zywicki and several others noted that Article I defines the legislative role of the vice president, and until the Nixon-Agnew administration, the vice president's budget came from the Senate. 

Well, fine, Biden misspoke. But what about his accusation that Cheney has improperly defined himself as part of the legislative branch in order to increase his power? And where does Palin's notion of an expanded role for the vice president in Congress fit into the argument?

Megan at Bunk in the West said Palin's statement constitutes an endorsement of the unitary executive theory, about which she says:

Under this theory, the president’s authority when acting as
commander-in-chief or when making foreign policy cannot be reviewed by
the judiciary or checked by Congress.

Megan also said the Bush administration has used the unitary executive principle to "abandon the rule of law:"

But Shannen Coffin, a former legal adviser to VP Cheney, says Biden and the Democrats have distorted the meaning of the theory:

 Democrats have never understood the unitary executive theory, which is
nothing more than a restatement of the first section of Article II: 
"The executive power shall be vested in a President of the United
States of America."  It is a simple "theory" of constitutional law —
that the President is the only Executive.

Annie Morrissey said Palin's statement marked an endorsement of the theory, and that should worry American citizens:

[T]he last twenty-four hours open a previously closed window on the
McCain-Palin view of governance and power, and it appears crystal clear
now that they intend to "govern" as BushCheneyRumsfeldYoo have
"governed" these last eight years. This is what is beyond terrifying.

 I'll say this much. Back in 2005, when the National Security Agency's warrantless surveillance program was revealled in the press, I wrote about my alarm that the president seemed to feel that his role as Commander in Chief gave him the right to ignore our government's principle of checks and balances. I still have that concern, and for that reason, I wish there were more opportunities to ask the presidental and vice-presidential candidates to explain their positions on these important constitutional principles.