I see lefty after lefty after lefty hyping this up for political reasons like some really awful thing. Yes, it was indeed a flub and should be learned from. Took me by surprise that we even have a group chat over a national security thing as important as this was.
But, what was really the bottom line of it all? Did it mess up our attack plans? No.
Did it expose classifed security to our enemies? Doesn't seem to have. As I understand it, the info was accidentally texted to a US reporter and, to the best of my knowledge, he did nothing nefarious with the information which would be traitorous to our country, therefore none of the flub had anything to do with anything detrimental to our country.
Yes, it was careless, just as Hillary Clinton's email server in her basement which could easily be hacked by our enemies was labeled extremely careless.
But, to the best of my knowledge, this is all a huge nothingburger being used as political ammo against Trump that does need to be fixed.