The government had the power to approve or block mergers of a certain size but the courts in their infinite wisdom decided the only thing that matters is if the companies involved claim it will lower prices for consumers if they merge (and no longer have a competitor to fight on price...). And also the courts seem completely unable to find a way to call bullshit and learn from the history of every other merger where prices inevitably go up (because they're under less competition).

Indeed, this was a neoliberal shift pushed by the Chicago school economics.

The neoliberals in government launched a nationwide campaign to educate judges that redefined antitrust from being about power (anything too big is bad) to be about demonstrable consumer harm (much harder to prove).

https://en.wikipedia.org/wiki/United_States_antitrust_law#Ri...