Bung: It's not easy to amend the Constitution. It looks like you need 2/3 of both the House and the Senate to agree on the amendment and 3/4 of the States to ratify it.

You don't really need to change it.  Like many other countries, the US reserves emergency powers for the President in case of, well, emergencies.  For example the Trading with the Enemy Act of 1917, extended with some WWII law whose name I can't remember and then the Emergency Economic Powers Act allows the president to rule by decree in certain areas.  Using the ongoing emergency of (from memory) the Korean War, presidential decrees which bypass congress have been ongoing for decades now.  The trick is to make them about things that people don't care much about, or that only a small group of people care about, so they don't get much attention.