I think trump is defining the differences, but I don't trust him because of his past
I think Jeb because of his brother has too much baggage with voters to ultimately win the presidency if he is the nominee for Republicans.
Yes, I agree Trump is defining the difference; he is seemingly also the main one countering hillary for now on some key policy points. Anyway, at this stage anything can happen. I still think Cruz is the best choice, though he may be viewed as ‘too conservative’ by the average voter.
BTW, I don’t trust any politician, and even Trump is one or he wouldn’t be in this process and doing rather well so far - it’s how each play and will play the political game that defines 50% of their viability & after becoming president, their performance & delivery. Hmm, Walker may be a good alternative to Trump or Cruz.