Lots of different people. 

Lots of other people. I know Carter didn't come to be president in a vacuum, but, he was weak as a president, in a bad way. (a weak president can be a generally good thing if it means less laws are enacted, in total. )  

 My impression is he was subverted much like Grant 

 Yes, that's part of the reason, for sure.  

 You might say for the same reason as trump 

 Pfft. Trump clotheslined himself with his truly awful appointees. He had no one to blame other than himself 🙄 

 Same as Grant