[To be read with this thread referenced at the top of the last entry.]
In 1927, the Supreme Court noted:
But there is no provision expressly investing either house with power to make investigations and exact testimony, to the end that it may exercise its legislative function advisedly and effectively. So the question arises whether this power is so far incidental to the legislative function as to be implied.
In actual legislative practice, power to seizure needed information by such means has long been treated as an attribute of the power to legislate. It was so regarded in the British Parliament and in the colonial Legislatures before the American Revolution, and a like view has prevailed and been carried into effect in both houses of Congress and in most of the state Legislatures.
This power was both asserted and exerted by the House of Representatives in 1792, when it appointed a select committee to inquire into the St. Clair expedition and authorized the committee to send for necessary persons, papers and records. Mr. Madison, who had taken an important part in framing the Constitution only five years before, and four of his associates in that work, were members of the House of Representatives at the time, and all voted for the inquiry.
It is questioned however by some because a "subpoena" has a certain judicial flavor, so why not require a judicial intervention? But, so does "testimony," but one testifies under oath/affirmation to Congress as well with no judge overseeing the immediate questioning. The word here means submission of material or testimony under penalty, in particular to Congress.
The Federalist Papers noted that our system is not some artificial set of powers with no overlap. Thus, Congress deals with military regulations, limiting executive discretion in the process in a key 'executive' matter. A judge has power over his/her court, contempt liable to put you in jail, even if not executive official charges you. And, executives make many rules w/o being deemed 'legislators.'
But, even here there are checks. Congress cannot require any testimony under the sun. In reality, this often a matter of political judgment -- though some (one citation of 'bear biting' or the like) suddenly don't like politics when it might harm their side.
But, the courts have repeatedly noted some limits. For instance, a 19th Century case ... seen now as an early security of privacy ... held Congress could not investigate (by subpoena) purely private matters. This was deemed a judicial function. It had to be 'legislative.' Likewise, during the Red Scare, the courts protected privacy and other rights from congressional overreaching.
We deal with public matters here. Thus, Charles Krauthammer - a conservative columnist -- suggests Alberto Gonzalez must go because he negligently let an underlining promote untruths to Congress (this misleading is criminal btw). The executive executes congressional laws. Congress funds it. It handles appointments. It has the ultimate oversight power of impeachment, which often leads to pressure/firing, thus impeachment is a rarity, like the death penalty of sorts.
But, what of executive privilege? First off, this is an implied power, but since congressional investigatory power is as well, that is not enough to damn it. It does seem that the two are not quite the same, since the very idea that material -- even quite relevant to congressional duties -- cannot even be shown is a quite weighty claim. One that even the press does not get to make completely to protect a source. The Congress investigates largely in public. Secrecy can be dangerous.
It has its place, so executive privilege is respected, though one might find it relevant that Clinton opened up his staff to congressional investigations. Others -- see Center for American Progress etc. -- note it is not a rare practice as Bush claims. And, executive privilege is surely not absolute. Per U.S. v. Nixon:
The President's need for complete candor and objectivity from advisers calls for great deference from the courts. However, when the privilege depends solely on the broad, undifferentiated claim of public interest in the confidentiality of such conversations, a confrontation with other values arises. Absent a claim of need to protect military, diplomatic, or sensitive national security secrets,
Now, the case involved judicial process, but the basic sentiment expressed can apply as well to the legislative branch. In our system, there are many ways to secure the public interest, including our representatives. Thus, the ruling at once pt noted:
In designing the structure of our Government and dividing and allocating the sovereign power among three co-equal branches, the Framers of the Constitution sought to provide a comprehensive system, but the separate powers were not intended to operate with absolute independence.
While the Constitution diffuses power the better to secure liberty, it also contemplate that practice will integrate the dispersed powers into a workable government. It enjoins upon its branches separateness but interdependence, autonomy but reciprocity.
So a balance applies. Such balance again often works outside of the courts with various realities. One reality is that the executive, esp. certain individuals, warrant less respect and trust by this point. Let's say Karl Rove ... whose trouble telling the truth is known. This 'reality' is also expressed thru the political process. "Election has consequences." This includes actual investigations of possible and clear wrongdoing. If strictness is threatened, whose fault is it really?
Finally, back to the subpoena matter. I'm not sure where the demand for judicial subpoenas in this legislative arena will take you. First off, if the President rejects the Congress' demands, it can go to the courts. Second, what test would be required? I assume relevancy to a legislative purpose. A 'crime' is not the test.
It's clearly there, from fears executive officials lied to Congress on down. So, though long practice shows the Congress has the right to subpoena executive officials, court process seems almost pro forma here. So, the executive is left with absolutism and fictional appeals to the unitary executive as some defense of the public good. Yeah, that has met the test of time, hasn't it?
But, fiction has found its place here. Claims that "Clinton did it too," "obviously no crime occurred," "it's all political" (politics a bad word, of course), "nothing special happened here," "no crime happened so what's the deal?" etc. Fiction has its place. Not sure if it's here.