I don't think they should be off limits. What a spouse says and does is fair game. The same thing applies to Bill Clinton, Michele Obama, Heidi Cruz, and yes, Melania Trump.
I could care less that Heidi use to work for Goldman Sachs, but some people might care. I could also care less that Melania posed nude, but some people might care about that too.
However, it's not okay to insult and degrade a spouses looks. I think Trump found that out.
Well, perhaps as women we are more sensitive about looks (i hope I can say that in the PC world in which we live); however, Melania was the object of eh, well not an insult, but it was very degrading what the Cruz PAC did to her with a 16 year old picture, and Cruz did nothing to dial it down or call it back...No criticism—Tho it probably was not wisest thing to do, I can understand why Trump tweeted the pic of Heidi that he did. As I understand it, it was the Cruz campaign manager who requested rights to Melania’s pic from GQ.
I personally did not appreciate the lack of support from Cruz towards Trump and the Chicago Rally supporters.