What is Tom Robinsons predicament? How is he in a no-win situation that day at Mayellas house(inference)?

Tom had the audacity to feel sorry for a white girl. He tried to help Mayella but is falsely accused of rape. Tom simply cannot win this. The word of a white man, even if it's Bob Ewell, trumps the word of a black man. It is obvious to the jury that Bob Ewell raped and beat his own daughter: the bigotry in this town was still too ingrained for the jury to accept the truth.