This points out what people are overlooking: Bush and Kasich at the bottom of the pile are in easy striking range of Christie and Rubio at the top, (and of Cruz who is tied with them). In theory, Bush, having the most money, should be able to spend his way to the top, but his spending has been completely ineffective. Also, because it's all SuperPAC $ and campaign $ gets better rates, Rubio will be able to hang with him in ads. I briefly thought Kasich being excluded from the Trump Debate would cut off his oxygen but on the other hand, Kasich boosted his numbers by spending in NH even before the first debate. And Christie similarly didn't seem hurt by one debate demotion.
My bet is still Rubio to do best of these 4. I think the press about him neglecting traditional campaigning was a lucky break in that it alerted him to course-correct. I think Christie will have a glass jaw to attack ads. Not sure what Bush's favorables among NH Republicans are but my hunch is probably too low with too little time to fix. I'd bet Romney will endorse Rubio in January. He reportedly likes Kasich and holds no grudge against Christie but it just seems Rubio is his favorite. Trump would unleash a fit about Romney choking in 2012 and Rubio being a puppet, but that probably wouldn't hurt Rubio among the voters deciding between these 4. There's a chance Rubio could catch Trump, a better chance he could pull ahead Cruz but even if he did neither, he'd winnow his lane. Predictions aside, I'm rooting for Christie to win this division. Hard to imagine Cruz not being a finalist but Trump and Christie alsbeing final three and throwing down in March with high stakes would be glorious.