Charlie Cook: “Iowa should win­now the more con­ser­vat­ive half of the GOP field, likely end­ing the cam­paigns of Mike Hucka­bee, Rand Paul, and Rick San­tor­um and al­low­ing Ted Cruz to con­sol­id­ate the more strongly ideo­lo­gic­al wing of the party. Con­versely, New Hamp­shire is likely to cull the herd of con­ven­tion­al Re­pub­lic­an can­did­ates—Jeb Bush, Chris Christie, John Kasich, and Marco Ru­bio. All are not likely to re­main con­tenders after the Gran­ite State votes.”

“The only ques­tion is wheth­er New Hamp­shire will push one or two of the con­ven­tion­al can­did­ates from the race, or even three if there is a big gap between the first-place es­tab­lish­ment can­did­ate and the run­ner-up. Thus the res­ults and fal­lout from Iowa and New Hamp­shire should provide a lot more clar­ity to a race in which Re­pub­lic­ans were faced with a dizzy­ing ar­ray of choices, much like a kid walk­ing in­to Baskin-Rob­bins for the first time.”

A new American Research Group poll in New Hampshire finds Donald Trump continues to lead the GOP field with 31%, followed by John Kasich at 17%, Ted Cruz at 12%, Marco Rubio at 9%, and Chris Christie and Jeb Bush at 8% each.

On the Democratic side, Bernie Sanders leads Hillary Clinton 49% to 42%.

Greg Sargent: “If the GOP nominee tries to win primarily by increasing the white vote, it would not only require a very large mobilization of whites, and/or very high levels of support among them, but it would also require the minority share of the vote to remain somewhat depressed relative to what demographic trends dictate. But the very rhetoric and proposals needed to mobilize and/or win over whites in that fashion would probably energize minorities in opposition and potentially drive away some college educated whites — both of which would work against the overarching goal of the strategy in the first place.”

“For months, the tumultuous Republican presidential primary has masked a brewing debate among Democrats about their own party’s future,” the AP reports.

“Now, with Sen. Bernie Sanders chipping away at Hillary Clinton’s grip on the Democratic nomination, the differences are spilling out into the open as the candidates campaign across snow-covered Iowa.”

“At its core, the divide between Clinton and Sanders is about just how much to change current economic, health care and education systems, and what the federal government’s role in those areas should be. The candidates often share the same goals, but have different policy prescriptions and preferred tactics for achieving them.”