Trump +27% over Cruz.
Trump has this race in the bag, just like Clinton had the race in the bag against Obama in 2008!
RCP Polling Averages Democrat Party December 2008
Pew research 12/19 - 12/30 Clinton +20
FOX News 12/18 - 12/19 Clinton +29
Cook/RT Strategies 12/15 - 12/17 Clinton +12
NBC/WSJ 12/14 - 12/17 Clinton +22
USA Today/Gallup 12/14 - 12/16 Clinton +18
Rasmussen 12/13 - 12/16 Clinton +13
Reuters/Zogby 12/12 - 12/14 Clinton +8
National polls this far out, when people are not tuned into the race and focusing on the holidays don't mean much for predicting who will win the primaries
http://www.realclearpolitics.com/epolls/2008/president/us/democratic_presidential_nomination-191.html
Not long now we will see soon enough.
Your glaring error is thinking Hillary Clinton and Donald Trump are similar candidates.