Unnamed sources attacking Cruz: Unsubstantiated rumor!!
Unnamed sources attacking Trump: This is A-OK! Impeccable reporting from a trusted source!
Your post implies a parity that does not exist.
I hear what you are saying about “unnamed” sources and agree, as to both candidates.
But Trump personally tweeted the picture of Heidi himself, so there is no need for a “source.” Trump did it.
It’s a bit different when unnamed sources are simply offering an opinion, rather than being cited to allege some major impropriety.