Is there anyone from that era who could conceivably become Attorney General and try to crack down on lynching? Upon looking through it seems there are several Republicans of the time who played around with various voting and civil rights act bills aimed at helping out African Americans; could one of them have risen to the challenge?
There's also the inevitable impeachment hearing with the AG vs the Senate. How would this go? I'm picturing an Atticus Finch type character rising to the occassion, a strong personality who can do this with or without Teddy's help (but most likely brought on board by Teddy ITTL).
Just so it's clear, I'm thinking the 1910s after a successful Teddy re-election. Failing that, we could also discuss some action being done during Teddy's first two terms (1900-1908).