They just elected Claudia Sheinbaum, who is seen as being extremely close to the outgoing president AMLO. Some people were suggesting that she was so close to him that it was really his way of getting another term as president, similar to how Putin stepped down as president of Russia to become PM while Dmitry Medvedev became president in name only.

How true is that? It's hard to say. My guess is that a lot of it is sexism, thinking that a woman can't think for herself and a woman president will turn to someone else for the important decisions.

But, it's true that under AMLO, there was a lot of democratic backsliding in Mexico. OTOH, Mexico has been dominated by PAN and PRI for decades. In fact, PRI won 14 elections in a row between 1928 and 1994. It wasn't until Vincente Fox in 2000 that PAN was even a factor. So, there's a lot of the power structures in Mexico geared towards supporting PRI and PAN.
They were probably undermining a lot of the things AMLO wanted to accomplish. If he had followed all the rules and norms he might not have been able to accomplish anything because the establishment would have blocked everything he tried to do. That doesn't excuse his rule and law breaking, but it does contextualize it.

We'll see what happens with Sheinbaum. I, for one, am fucking thrilled that Mexico's president has a PhD in energy engineering. The fact she's a woman is also historical, but to me the doctorate is more important.