If you consider gun control as a violation of the 2nd Amendment....
... and you consider the gun ban and the Brady law as gun control...
... and you consider the upholding the 2nd Amendment as a plank in the Republican platform...
.. then Kasich betrayed his Party on that issue, and if he would betray the Party on what many consider an important issue, there is no reason to believe, that under certain conditions, he may betray other issues as well.
If that's what a RINO is, then he obviously qualifies. It isn't so much that he threw out one plank of the Party, it's that he found it expedient to do so. And that he thought he'd gain something through 'bipartisanship'.
Well, he did gain something - the temporary "respect" from the MSM liberals, but he lost at least my vote and my respect along with that.
Granted he is not perfect, but you cranks who expect perfect is living in a dream world.