The main impact of Iowa on the Democratic side is that the party is digging in for a competitive race and, more importantly, the media coverage of Sanders was as infrequent as they could get away with, which has to change and has so far. Voters nationally that haven't heard Sanders explain his positions are tuning in. Reporters are taking dictation from Clinton propagandists in newspapers, Politico, etc, to the effect that Sanders is unelectable without noting in even the last paragraphs that head to head polls, usually unfavorable to candidates with lower name recognition, place Sanders clearly ahead of Republican rivals while Hillary is losing them. These papers do mention in other articles Clinton's false statements about emails and some of her fundraising conflicts of interest, but rarely mention that Bill Clinton is on over a dozen captain's logs flying on a private jet with a trafficker of underage sex slaves and the slaves themselves, which perhaps they're saving for the general election.
The two Cuban exiles had a bounce from Iowa and squandered it before the week was out - Cruz, trying to win the evangelical 'lane' nationally, would I think have won the state without robocalling that Carson had dropped out, but gave his rivals a talking point against him which appears to be combining with New Hamphire's resistance to sanctimonious Iowa victors to make for low poll numbers up there. Rubio's perf in Iowa seemed to put him much more within reach of claiming to be the figure the establishment and the victory-seeking rank and file would unite around but the debate blew the lid off the denial that he was a lightweight, as Christie and Bush began to shout that long-held belief that insiders had whispered.
I actually like what Cruz is saying about not fighting both Assad and ISUS at the same time, suggesting he thinks out his own positions instead of fronting for covert proxy wars - sometimes (!). I oppose him for the obvious policy reasons. He will stay in the race for a while, bankrolled by Texas oil money despite Republican insiders' hatred of him. I believe it is possible for a conservative Cuban exile to transcend a nostalgia for the corruption of Batista-era Havana. In Rubio's case, being a opportunist puppet of an organized crime linked casino owner (Adelson) with "some very, very curious and disturbing political bedfellows" doesn't seem to be the way to do that, and I am quite relieved by any news of his demise. Rubio's similarities to W. Bush are also striking - a lightweight who cuts a good media figure in choreographed moments and cedes US foreign policy to the most extreme Neocons, but may actually be good on immigration. Likewise I get relief from simple blessings like Rick Santorum dropping out - think of all the children of the world living under people like him..
Kasich seems primed for a big night, close to winning the whole thing, and Sanders' NH lead has increased in polls since Iowa. Sanders and Kasich would be a gift to the country from the Granite State - in addition to representing the left option of each party's linear spectrum, Kasich as the nominee significantly reduces the bogeyman factor compared to his GOP rivals. Based on his past statements, it's likely he'd discourage congress from voting again to overturn Obamacare, and if they ignored him, he'd probably veto it. His own imprint on health policy would likely follow his call for a Medicare expansion, defending Obamacare by saying "when you die.. St. Peter.. is going to ask you what you did for the poor." He can be expected to perform better on this as president than Hillary. Both Kasich and Hillary are Wall Street linked free traders that combine an acknowledgment of the human impact on the ozone layer with a resistance to active regulation - as the Clinton-Gore administration classified SUVs as light trucks to circumvent emissions standards. Kasich's statements on virtually every aspect of US foreign policy have been less hawkish than Hillary's.