I take your point, but exactly how did Trump “allow” the Post to publish that photo? And shouldn’t “Donald Trump and the Post are hanging Melania out to dry” read “Hillary Clinton and the Post …”? Exactly how does Trump gain advantage out of this, as you allege? It is Hillary and the Democrats who gain advantage. You correctly disparage the tactic, but are tying yourself in a knot trying to pin the blame on Trump, instead of on the anti-Trump forces where it belongs.
There is another, larger angle to this. Democrats only support women and their freedom to flout convention when they are on the Left. It only took a few minutes for them to pounce most viciously on Sarah Palin. Other successful and accomplished Conservative women have gotten the same treatment from Democrats. Same can be said of Conservative blacks.
Melania’s offense in their eyes has nothing to do with modeling nude, or her marriage to Donald, or any behavior that the Left praises in Liberal women; it simply is that she is a Conservative woman.