What's your thought on this matter?
I agree that it was not off the cuff. My sense is that for whatever reason, right or wrong, he doesn't respect her, and he is indifferent about getting her support. He didn't buy the reason she gave for not appearing at the rally. He may think she is weak on immigration.
Susana Martinez, the Yin to Donald Trump's Yang? - NBC News - Apr 25 2016
Following [self-proclaimed genius Bill] O'Reilly's comments the Governor's Press Secretary said she had no intention of entering the fray as a vice presidential candidate. Not surprising given Martinez endorsed fellow Latino Republican Marco Rubio and denounced Trump's comments about Mexican immigrants even leaving open the possibility that she wouldn't vote for him.
We don't know what happened behind the scenes either. He or the campaign may have had discussions urging her to appear, including discussions around her given reason. If she doesn't want to support him, using a pretext of prior engagements, his reaction is just a negotiating device. He's willing to walk away from the table. Is she?
She is part of the #NeverTrump cabal, I believe.
Martinez hit Trump. Trump hits back. Simple enough.
She was on the NeverTrump bandwagon and has tried to take him down along with the other so called conservatives. Trump does not bend to brazen disloyalty.