making Andrew break up with Mellie was legitimately one of the cruelest things Fitz did to her legitimately.
like it might not seem all that significant but let’s think about it:
For Fitz to win, Mellie cannot leave him on the trail and will probably have to stay with him through the second term (so far as we know in Season Three). Fitz is actively having an affair with Olivia, and has made it clear that he does not care about Mellie, and may in fact hate her. This means, he has effectively decided unilaterally that Mellie should suffer in silence the rest of his presidency. She has no one else, Fitz will barely speak to her, he will not even let her have this one thing.
like I’m not putting this well, but essentially it’s total forced isolation. He wants her to just sit there and wait for him while he sleeps with another women (which she at this point is just letting him do! he has everything he wants!) and he won’t even let her have someone that makes her happy. Honestly it’s just sad.