Another problem with the Separation of Powers Principle as it exists under our Constitution is that the division of responsibility as instituted obliterated accountability. This effect was noted by Hazlitt:
Congress can prevent the President from doing as he wishes but cannot make him do what it wishes. Responsibility is divided and lost even within Congress itself. The Senate can block the overwhelming will of the House, though that will may reflect an equal sentiment in the country. Worse, a single Senate committee chairman, chosen by seniority, can often block the expressed will of the House and prevent the Senate from expressing a will by his mere inaction.
The result of this system, even in their quiet times, as Bryce pointed out, is that the nation does not know 'how or where to fix responsibility for misfeasance or neglect,' and 'no one acts under the full sense of direct accountability.'
According to author Harold Laski,
It is desirable that the source of responsibility for governmental error or wrong should be clear and unmistakable; the American system so disperses responsibility that its detection is approximately impossible. It is urgent that the working of institutions should be conducted in the perspective of discussion which educates and clarifies the public mind; but the essential tasks of operation in America are almost wholly concealed from the public view. . . . A governmental system, moreover, should be sensitive to the opinion of its constituents, and maximize the opportunity of translating a coherent body of doctrine into statute; yet it seems the purpose of American institutions deliberately to avoid the sensitiveness, on the other hand, and to prevent the making of coherent policy upon the other. 
Accountability was one of the chief victims of the Separation of Powers. According to Hazlitt, "The great defect of the American system is not merely that it can bring deadlock between . . . the two houses of Congress . . . but that it usually becomes impossible to fix the precise responsibility for that deadlock or to do anything about resolving it." Hamilton viewed this ultimate consequence of the actions of the Framers in a negative light. As he stated with regard to division of responsibility in the Executive Branch, plurality (assigning the execution of a responsibility to two separate people or bodies) would obliterate accountability:
[P]lurality . . . tends to conceal faults and destroy responsibility. . . . It often becomes impossible, amidst mutual accusations, to determine on whom the blame or the punishment of a pernicious measure, or series of pernicious measures, ought really to fall. It is shifted from one to another with so much dexterity, and under such plausible appearances, that the public opinion is left in suspense about the real author. The circumstances which may have led to any national miscarriage or misfortune are sometimes so complicated that, where there are a number of actors who may have had different degrees and kinds of agency, though we may clearly see upon the whole that there has been mismanagement, yet it may be impracticable to pronounce to whose account the evil which may have been incurred is truly chargeable.
'I was overruled by my council. The council were so divided in their opinions that it was impossible to obtain any better resolution on the point.' These and similar pretexts are constantly at hand, whether true or false. And who is there that will either take the trouble or incur the odium of a strict scrutiny into the secret springs of the transaction? Should there be found a citizen zealous enough to undertake the unpromising task, if there happen to be a collusion between the parties concerned, how easy it is to clothe the circumstances with so much ambiguity, as to render it uncertain what was the precise conduct of any of those parties?
[T]the people remain altogether at a loss to determine by whose influence their interests have been committed to hands so unqualified, and so manifestly improper. . . .
[P]lurality . . . tends to deprive the people of the two greatest securities they can have for the faithful exercise of any delegated power, first, the restraints of public opinion, which lose their efficacy, as well on account of the division of the censure attendant on bad measures among a number, as on account of the uncertainty on whom it ought to fall; and, secondly, the opportunity of discovering with facility and clearness the misconduct of the persons they trust, in order either to their removal from office, or to their actual punishment, in cases which admit of it.- Advertisement -
This issue is only too contemporary. Take, for example, the topic of the National Debt. Congress blames the President. The President blames Congress. The House blames the Senate, and the Senate blames the House. The Democrats blame the Republicans, and the Republicans blame the Democrats. Who's at fault? As Woodrow Wilson wrote in 1886:
It is . . . manifestly a radical defect in our federal system that it parcels out power and confuses responsibility as it does. The main purpose of the Convention of 1787 seems to have been to accomplish this grievous mistake. The 'literary theory' of checks and balances is simply a consistent account of what our constitution-makers tried to do; and those checks and balances have proved mischievous just to the extent to which they have succeeded in establishing themselves as realities. It is quite safe to say that were it possible to call together again the members of that wonderful Convention to view the work of their hands in the light of the century that has tested it, they would be the first to admit that the only fruit of dividing power had been to make it irresponsible. 
Power is divided under our Constitution not only because legislation must pass two separate Legislative bodies in identical form, and not only because legislation must also survive a potential Presidential veto, but because legislation, even if passed, must be enforced by the Executive Branch. In point of fact, passage of legislation is only the first hurdle; in actual practice, laws can be vitiated by an Executive Branch which does not "take care" that laws be faithfully executed, as required by the Constitution. This Accountability violation was reflected in the headline to an article appearing in The New York Times - "Congress and Administration Trade Blame for Keeping Legislation on Shelf":
Because of bureaucratic foot-dragging, complex directives from Congress and in some cases ideological hostility, the Federal Government has failed to carry out major parts of health, environmental and housing laws passed with much fanfare in recent years.
The delays have left Congress stymied, consumer groups frustrated and businesses sometimes paralyzed in the absence of prescribed regulations. . . .
Bush Administration officials acknowledge that they have missed many of the deadlines set by Congress for the new laws. But they say Congress is partly to blame because it writes laws of impenetrable complexity with countless mandates and gives Federal agencies insufficient time to write needed regulations.
Federal officials say the problem has become more widespread in recent years. They cite these examples:
Two decades after Congress ordered the Environmental Protection Agency to identify and regulate 'hazardous air pollutants,' the agency has issued emission standards for only seven chemicals.- Advertisement -
END PART 7: TO BE CONTINUEDFOOTNOTES
 A New Constitution Now, pp. 4-5.
 A New Constitution Now, pp. 44-5, quoting Harold Laski, The Dangers of Obedience (1930).