Not only was Trump's comment at odds with our constitution, but it was tactically idiotic as well.  Does anyone think that judges aren't going to stick together when the legitimacy of their institution is challenged?  
When you get pulled over by a cop you might challenge his interpretation of events ("it was the truck that passed me that was going 85...I was only going 60 - your radar gun picked up the wrong guy"), but you're downright stupid to tell the cop that he doesn't have the authority to issue a traffic ticket.
The next Trump issue that lands in front of a federal judge (which will be a weekly occurrence) may be affected by his unhinged twitter thumb this time.