Suppose you were an idiot. And suppose you were a member of Congress. But I repeat myself.

America is a nation without a distinct criminal class with the possible exception of Congress.

The provision of the Constitution giving the war making power to Congress was dictated, as I understand it, by the following reasons: Kings had always been involving and impoverishing their people in wars, pretending generally, if not always, that the good of the people was the object. This our convention understood to be the most oppressive of all kingly oppressions, and they resolved to so frame the Constitution that no one man should hold the power of bringing this oppression upon us. But your view destroys the whole matter, and places our President where kings have always stood. * Letter, while US Congressman, to his friend and law-partner William H. Herndon, opposing the Mexican-American War (15 February 1848)

Dealing with Congress is a matter of give and take. The president doesn't get everything he wants, the Congress doesn't get everything they want. But we're finding good common ground. A dictatorship would be a heck of a lot easier, there's no question about it.