Anti-Trust is not magic, its no longer a tool politicans can wield like a club against things they don't like. The courts have a definition and you actually have to prove abuse for those law-suits to do anything. Doing so if you can do it at all takes decades.
Unless politicians make major changes to the anti-trust law its unlikely to be effective. And doing so would require major action in congress.
The president could use non anti-trust actions as well of course. But rather unlikely.
Sure, but sometimes the threat of doing something and having an acquisition mired in a lawsuit or the Prez using the bully pulpit against your co can be a serious deterrent from engaging in an acquisition as well.
You don't need Congressional action - the laws never changed, the definition of the courts did. Biden is appointing federal judges faster than even Trump did, so the opinion of the courts may be shifting very quickly.
Unless politicians make major changes to the anti-trust law its unlikely to be effective. And doing so would require major action in congress.
The president could use non anti-trust actions as well of course. But rather unlikely.