Time was when Americans had a healthy regard for human frailty and the dangers of an imperial Executive Branch, President, Congress, and absolute power concentrated within the Federal Government. The framers of the Constitution installed enough safety devices in the system, they believed, to give hope that future generations wouldn't have to deal the inevitable tendency of those in power to accumulate more power.
The framers trusted the population, an uneducated, but common-sense citizenry, to mistrust a strong central government.
It took an extraordinary circumstance to give the first Imperial President an opportunity to circumvent the Constitution and seize absolute power for a while. One-half of the Congress absented itself from the proceedings. The serving President refused for two months to negotiate with them, even meet with them, but, during that time-span, because of the impotence of Congress to act, accrued enormous power by default to the presidency.
When war broke out, it was a presidential war, the first in the history of this nation. One half of the population of this country, by order of the president of the United States, used force of arms to impose its will on the other half, completely without any pretence of advice and consent of Congress, vote by the population, anything but the will of the executive. Abraham Lincoln.
The result was the bloodiest war in US history until Vietnam.
For several generations following the Civil War mistrust and fear of Executive power returned to the citizenry. Even the winning side could easily see, without dwelling on it, the mischief wrought by absolute power in the seat of the Presidency. For an interval of several decades after Reconstruction there was a renewed respect for strict adherance to the Constitution in all matters, including formal declaration of war by Congress.
Prior to the Great Depression and the election of Franklin Roosevelt, the standard response to efforts of any branch to seize power beyond that defined in the Constitution was mention of the reminder that 'if we don't like something in the Constitution, there's a mechanism for changing it through amendment'.
That response carried enough weight to bring about a Constitutional Amendment to confine the number of terms a US President could serve in office (now 10 years), following the four-term President-for-Life administration of Franklin Roosevelt.
But after WWII, the Cold War offered extraordinary arguments once again for an Imperial President waging wars without the consent of Congress, supported by a committee of nine Supreme Court judges to amend the Constitution without having to formally amend it.
That's gone on so long, when the Cold War ended the population was too young to remember anything else, to remember that there's a document called the US Constitution, that it defines the powers of each branch of government, provides means to amend itself.
Outmoded, outdated, that Constitution. Overwhelmed by the abdication of power by Congress, human frailty, human cowardice, blind, sheeplike trust in mama government by the citizenry.