"The executive Power shall be vested in a President of the United States of America."
Executive power is vested in the President, not the Vice-President.
"He shall hold his Office during the Term of four Years, and, together with the Vice President, chosen for the same Term, be elected, as follows:"
This states that the terms of President and Vice-President run concurrently and they are elected at the same time, but does not place the VP in the executive branch itself.
The powers of the Vice President are spelled out in Article I, Section 3 where the VP is the President of the Senate responsible for procedural matters and breaking ties in the Senate. Since he is rarely needed to do this, he is rarely in the Senate in modern times. The VP sitting in on cabinet meetings is relatively new in U.S. politics.
Anything that Bush told Cheney, any documents sent to Cheney's office, were made available to the President of the Senate, which is, of course, constitutionally in the legislative branch of government.
It appears that in doing so, any claim of "executive privilege" has been waived!
"Growth of the office
For much of its existence, the office of Vice President was seen as little more than a minor position. John Adams, the first vice president, described it as "the most insignificant office that ever the invention of man contrived or his imagination conceived." §Even 150 years later, 32nd Vice President John Nance Garner famously described the office as "not worth a pitcher of warm piss" (at the time reported with the bowdlerization "spit"). Thomas R. Marshall, the 28th Vice President, lamented: "Once there were two brothers. One went away to sea; the other was elected vice president. And nothing was heard of either of them again." When the Whig Party was looking for a vice president on Zachary Taylor's ticket, they approached Daniel Webster, who said of the offer "I do not intend to be buried until I am dead." The natural stepping stone to the Presidency was long considered to be the office of Secretary of State. It has only been fairly recently that this notion has reversed; indeed, the notion was still very much alive when Harry Truman became the vice president for Franklin Roosevelt.
For many years, the vice president was given few responsibilities. After John Adams attended a meeting of the president's Cabinet in 1791, no Vice President did so again until Thomas Marshall stood in for President Woodrow Wilson while he traveled to Europe in 1918 and 1919. Marshall's successor, Calvin Coolidge, was invited to meetings by President Warren G. Harding. The next Vice President, Charles G. Dawes, was not invited after declaring that "the precedent might prove injurious to the country." Vice President Charles Curtis was also precluded from attending by President Herbert Hoover.
Harry Truman had been vice president only three months when he became president; he was never informed of Franklin Roosevelt's war and postwar policies.
Harry Truman had been vice president only three months when he became president; he was never informed of Franklin Roosevelt's war and postwar policies.
In 1933, Roosevelt raised the stature of the office by renewing the practice of inviting the vice president to cabinet meetings, which has been maintained by every president since. Roosevelt's first vice president, John Nance Garner, broke with him at the start of the second term, on the Court-packing issue, and became Roosevelt's leading political enemy. Garner's successor, Henry Wallace, was given major responsibilities during the war, but moved further to the left than the Democratic Party and the rest of the Roosevelt administration, and was relieved of actual power. Roosevelt kept his last vice president, Harry Truman, uninformed on all war and postwar issues, such as the atomic bomb, leading Truman to wryly remark that the job of the vice president is to "go to weddings and funerals." The need to keep vice presidents informed on national security issues became clear, and Congress made the vice president one of four statutory members of the National Security Council in 1949.
Richard Nixon reinvented the office of vice president. He had the attention of the media and the Republican party, and Eisenhower ordered him to preside at Cabinet meetings in his absence. Nixon was also the first vice president to temporarily assume control of the executive branch; he did so after Eisenhower suffered a heart attack on September 24, 1955; ileitis in June 1956; and a stroke in November 1957.
President Jimmy Carter was the first president to formally give the vice president an office in the West Wing of the White House.Despite the mostly minor role, some Vice Presidents are regarded as powerful politicians while in office (i.e. Martin Van Buren, Walter Mondale, George H.W. Bush, Al Gore and Dick Cheney)."
http://en.wikipedia.org/wiki/Vice_President_of_the_United_States