Before getting into tactical considerations, let me reiterate that an alpha male shooting the shit in private with a few other guys is harmless.
Even more, it's cathartic for a lot of men. In an increasingly feminized world where men have fewer and fewer venues in which they are able to interact exclusively with other men, they're forced to communicate using female-friendly language. Mixed-sex groups invariably move towards female norms of behavior and away from male norms of behavior, so the breakdown of gender barriers inexorably leads towards the breakdown of masculinity itself.
To condemn it is essentially to condemn virility. Hardly coincidental.
The skirt-clutching is disingenuous. Popular culture is full of stuff far 'worse' than anything Trump talked about.
In the case of Fifty Shades of Grey, we have simulated sexual assault being depicted favorably--textually and on-screen--for the purposes of entertainment and in front of a national audience.
In the case of Game of Thrones, we have terrible acts being depicted--verbally and visually--for the purposes of entertainment in front of a national audience.
Trump is depicting less terrible acts--and only verbally--for the purposes of entertainment to a few guys in private who are having fun with it.
That said, Trump's apology hit all the right notes. Especially effective was the remark that campaigning has changed him. This is a rare instance in his presidential campaign where it has made political sense to offer one, and as much as is possible given the circumstances, he did it from a frame and position of strength:
Social media confirms. Trump's post has, at the time of publishing, an astounding 350,000+ shares, 20 million views, and nearly half a million likes. We're not scattering, we're rallying:
Those are astronomical figures even for Trump, whose posts regularly get around one-tenth of those numbers.
Three primary reasons for the positive assessment:
1) Trump "never" apologizes. So the fact that he is apologizing becomes a story in itself.
2) It really is a distraction. That's something people are looking for in Trump, a move away from distractions. He's delivered on that desire, to the point of frustration for many of us in the first debate.
3) The gloves need to come off tonight, but the optics will be better for Trump if Hillary (or the moderator or a questioner in the audience) brings the remarks up. This will 'force' Trump to drag Hillary into the mud, an environment he's more adept at navigating.
Trump says it was private, lewd locker room talk between a couple of guys shooting the breeze, he wasn't running for office at the time, and he's expressed regret. He then calls on Hillary to apologize for the women she intimidated with mafia tactics so her husband could get away with rape. Hillary doesn't want to go down this road.