Is it a good idea regardless of the political merits?

That's quite debatable. What is clear, though, is that the city's current airport is bursting at the seams.

They opened another airport instead, but it's in suburbia.

https://en.wikipedia.org/wiki/Felipe_%C3%81ngeles_Internatio...

It's a good idea for Mexico City to substantially increase green space. However, it's also a good idea for the city to augment its air transport infrastructure. The AMLO government has made a bold decision, and time will tell how it works out.

The AMLO government made a populist decision. After burning $5B. He also vowed not to use the presidential plane that was already delivered and paid for, a 787, no less... They couldn't sell it, so it rotted for a few years until it was "donated" to an airline. Finally, they built another airport much farther away and with very little oversight over how the contracts were awarded.

So I think it's just another flavor of bad. And don't get me starter on AMLO's gutting of the electoral commission.

I think it is a good idea considering the temporal frame of reference. Payback on projects like these take decades. Furthermore the objectives of whichever local official with any sense of wit and honor most certainly must encompass and protect the needs of local citizens and global directives at the expense of energetically and ecologically expensive tech of arguably dubious merit.