Why does Lina get so much hate?

I don't understand why there is a certain segment that can't stop criticizing Lina Hidalgo. I get that a lot of people liked Ed Emmett, who by all accounts was a nice guy and had that soothing voice of calm during disasters, but looking back, his biggest accomplishment was saving the Astrodome from demolition. In 23 months on the job, Lina's actually done stuff that makes people's lives easier, like letting people vote at any polling location on election day. Is it because she's young? If so that's hypocritical because Emmett joined politics at 29. Also, they are both smart, she went to Stanford and he went to Rice. Or is it because she's liberal, or a woman, or someone that speaks Spanish? Honestly asking here.