That has nothing to do with them being a monopoly. Anti-trust law is not about the geographic spread of a company. What services are they a monopoly in? How are they abusing that monopoly power? What would be different if there were more competitors, or if they weren’t allowed to make those mergers?

Nothing in my comment had anything to do with "geographic spread" neither did I state they were a monopoly. My comment clearly states "it's not too far off."

Anti-trust law concerns the ability of a company to constrain competition. AT&T as the largest satellite provider(DirecTV) the seconds largest Cell Phone provider by customers and wireless spectrum holdings and now also owner of one of the largest media/content companies is very much in a position to "constrain competition. This potential to constrain competition was at the root of their failed $39 billion bid to buy T-Mobile 7 years ago.