What would the world be like if George Washington had declared himself king?

I have been reading a lot about the days after the revolution recently, and it seems to me that George Washington could have just grabbed power and no one would have been able to do anything about it.
He had full control and loyalty of the army, the entire country loved him. Hell, he is the only pres in history to get unanimously voted for by the electoral college.
Sure many of the other founders would have rumbled, but none of them, even collectively, had the support Washington did in the years immediately following the revolution.
Luckily he had a huge moral compass and a realistic opinion of himself. But what if he didn't....

What do you think America would look like today if he had taken power, declared himself king and established a monarchy with a roman style (senate+powerful king)?