Is it foolish to question whether the Vice President is part of the Executive Branch?

Glenn Reynolds -- in a NYT op-ed -- says no:

Article I of the Constitution, which describes the authority of the legislative branch, says that “the vice president of the United States shall be president of the Senate, but shall have no vote, unless they be equally divided.” Aside from the job of replacing a president who dies or is unable to serve, the only vice presidential duties that are spelled out in the Constitution are legislative in character.

The Vice President sloughs off on this job terribly, don't you think?

But if the vice president is a legislative official, then the exercise of executive power by the vice president raises important constitutional questions related to the separation of powers. The Supreme Court has held on more than one occasion that legislative officials cannot exercise executive power. The Court would likely dub this a “political question” that is beyond its purview, but Congress is empowered to remedy this sort of thing by legislation.

I think the better way to state the rule is that one branch cannot exercise the power associated with another branch unless a specific clause provides otherwise. Thus, the President has a legislative role because he's been given the veto power, and the Senate has a judicial role in trying impeachments, and so forth. So I don't think the specifically assigned legislative function means that the VP is not part of the executive branch.

Reynolds sees value in locating the VP in the legislative branch in order to be able to say that he's constitutionally forbidden to perform the executive function.

And Congress should do just that: pass a law to prohibit the vice president from exercising executive power. Extensive vice presidential involvement in the executive branch — the role enjoyed by Dick Cheney and Al Gore — is not only unconstitutional, but also a bad idea.

The reason a statute is needed is because the courts would be unlikely to enforce the constitutional limitation Reynolds perceives. Reynolds bolsters the constitutional interpretation by observing that it would also be a good idea, since it would keep the VP from becoming enmeshed in the sort of presidential problems that might, through impeachment or resignation, bring the VP into the presidency.

I don't really like the idea of Congress telling the VP what to do, and I'm not inclined to buy the constitutional argument either.