“A contested convention favors Sen Cruz,”
I don’t think so.
I think Cruz doesn’t have the snowball’s chance in you-know-where to get the R nomination. The GOPe is using him to try to stop Trump, but they will not let him be the nominee either.
After Wisconsin, Ted is on a roll downhill and fast. He’ll be mathematically eliminated after NY primary.
The GOPe lining up behind Sen Cruz is not the same thing as Sen Cruz "joining the GOPe". The GOPe is smart enough to know that Trump will be a disaster in the general and there is a real risk of losing the Senate and a slight risk of losing the House. They are calculating that Sen Cruz may actually win and if not the losses they might suffer won't be so bad.
If it's a contested convention and neither Sen Cruz or Trump is the eventual nominee then it's likely that they will lose worse than if Trump was on the ballot. The GOPe may be a lot of things, but they aren't dumb when it comes to them figuring out how to retain power. It will either be Trump or Cruz as the nominee and I would bet on Cruz.