He's not whining. Trump is freaking furious as are many Republicans from Colorado. The RNC National and Republicans statewide in an under the radar move voted last August to change the rules. I only found an article about the changes in the Denver Post.
Oh and the change to the rules was voted on during summer vacation with 6 members missing from the vote.
The changes were brought about to do exactly what happened. Deny an outsider delegates because last time round Santorum beat the crap out of RNC's golden child Romney.
By not having a primary public vote that in all probability would have gone to Trump, they could give insider Cruz the win without embarrassment. And then go YAY never Trump.
Trump was losing the the polls, why do you say he was going to win? You mean like he won Wisconsin after trailing in the polls? Oops, he lost ... But on this, funny how it didn't come up until AFTER he lost and it's not an issue in other States that he's benefited from arcane rules ...
Anderson Cooper to Trump: Didn't you know the rules? Trump, rants, doesn't answer