What is Oversight?

Nancy Pelosi, along with several Democratic Party strategists and Congresspersons elect, believe that it is the job of the Legislative branch to conduct oversight of the Executve branch. Let's perform a quick check:

The eighteen specific and enumerated limited powers of Congress granted by the Constitution:

1. "The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defense and general Welfare of the United States , but all Duties, Imposts, and Excises shall be uniform throughout the United States."
2. "To borrow Money on the credit of the United States; Congress may borrow money by issuing bonds or by other means."
3. " To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes."
4. "To establish a uniform Rule of Naturalization, and uniform Law on the subject of Bnruptcies throughout the United States."
5. "To coin Money, regulate the value thereof, and of foreign Coin, and fix the
Standard of Weights and Measures."
6."To provide for the punishmentof counterfeiting the Securities and current Coin of the United States."
7. "To establish Post Offices and Post Roads.
8. "To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries."
9. "To Constitute Tribunals inferior to the Supreme Court."
10. "To define and punish Piracies and Felonies commited on the High Seas, and Offences against the Law of Nations."
11."To declare War, grant Letters of Marquee and Reprisal, and make Rules concerning Captures on Land and Water.
12. "To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two years."
13. "To provide and maintain a Navy."
14. "To make Rules for the Government and Regulation of the land and naval forces."
15. "To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions."
16. "To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may e employed in the Service of the United States, reserving to the States respectively, the Appointment of Officers, and the Authority of training the Militia according to the disclipine prescribed byCongress."
17. "To exercise exclusive Legislation in all Cases whatsoever, over such District (not exceeding ten Miles square) as may, by Cession of particular States and the Acceptance of Congress, become the Seat of the Government of the United States, and to exercise like Authority over all Places purchased by the Consent of the Legislature of the State in which the Same shall be, for the Erection of Forts, Magazines, Arsenals, dock-Yards, and other needful Buildings."
18. "To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof."

Nope, don't see it.
There are three branches of the Federal Government, each with its own powers, rights and responsibilities. There is what is known as the "Separation of Powers," which prevents oversight of one branch over the other. Oversight is not part of the constitutional checks and balances.
The checks and balances are spelled out clearly in the Constitution. The Executive and the Judicial Branches can't write or enact legislation--that is the duty of the Legislative branch. Neither the Legislative, nor the Judicial Branch is enpowered to execute the laws. The Congress carries "into Execution" laws--that is it passes or refects the laws but does not have the means to enforce them. Nor may the Legislative or Judicial Branches dictate the movement of military troops. Congress has the duty to call the military into action, by enacting law to do so, but the actual deployment and movement of such troops is determined by the Executive Branch, with the President as Commander-in-Chief. Finally, It is the duty of the Judicial Branch, not of the other two branches of Federal government, to determine the constitutionality of an enacted and executed law. This, perhaps, is the most powerful of the separate powers, as it determines the limits to which the other two branches may act.
Oversight, as percieved by those in Congress, is a myth and a misconception. To interfere with the duties of the Executive Branch or the Judicial Branch as proposed by the new Congressional leadership designate, through subpoenae and investigation, is to overstep the boundaries set by Separation of Powers. Congress may obtain what information it needs to perform its legislative duties, but it may not control or participate in the execution or enforcement of those laws it passes.