“Lyin’ Ted Cruz just used a picture of Melania from a G.Q. shoot in his ad. Be careful, Lyin’ Ted, or I will spill the beans on your wife!” So blustered Donald Trump on Twitter — his regular refuge for hurling insults at the chosen victim of the day. But this time, Trump had good reason to be angry, though it wasn’t Ted Cruz’s fault. Make America Awesome, a PAC run by Liz Mair, released an ad complete with a nude photo of the Slovenian-born Melania Trump, shot in 2000, and the text “Meet Melania Trump, your next first lady. Or, you could support Ted Cruz on Tuesday.” The implication was that we shouldn’t want someone like Melania as first lady. Leaving aside the actual merit of that argument for voters to decide, the ad was in poor taste — even if the woman did in fact have her picture taken in said pose, and even if she is Trump’s third wife. No other prospective first lady would be treated that way, nor should they be.

Obviously, any man is going to — and should — stand up for his wife, as Trump did. Cruz didn’t mess around, either, responding, “Pic of your wife not from us. Donald, if you try to attack Heidi, you’re more of a coward than I thought. #classless”

It’s not new for the first lady to be politically targeted, especially given that it’s often a politicized role. Think Michelle Obama and her nanny state school lunch program, or Hillary Clinton and health care. But any of those criticisms should be rooted in substance, not fluff. Melania Trump’s photo shoots have nothing to do with anything in this campaign. The fluff is precisely why Trump is such a frustrating candidate to us, but attacking him with fluff doesn’t work. Just ask Marco Rubio.