Woodrow Wilson was one of the most arrogant President's this country ever had. Not to mention he was a racist, which was prevalent at the time, against women's rights and greatly disliked the "Bain of Humanity" the poor. Which is kind of funny because he claimed he was a born again Christian.
It is rather hard to judge who is the most arrogant or worse but Wilson is up there. Andrew Johnson also has to rank up there. Because of the attempt on his life he purged the South. It would have been a lot worse had it not been for Congress and U.S. Grant running for President.