Today is the Iowa Caucuses, which starts off the 2016 presidential primary season, even though it's a caucus and not a primary!
The most recent polling shows a tight race between Hillary Clinton and Bernie Sanders on the Democratic side. The fact that it's a caucus format in a predominantly white state may give Sanders the edge.
On the Republican side, it's a tight race between Ted Cruz and Donald Trump. The fact that Cruz gave a poor showing in the last GOP debate, and Trump somehow won despite boycotting the event, may give Trump the edge.
The biggest impact that the Iowa Caucus is likely to have, in either party, is to give Sanders some extra momentum if he ekes out the win. That said, it will also probably mean the media gives him significantly more scrutiny than they have thus far, so a win could be a "careful what you wish for" situation for his campaign.
I don't expect that it will matter to the Republican primary at all, frankly. It isn't likely to create any new dynamics in the race, nor is it likely to be a predictor of the ultimate nominee. By way of reminder, Rick Santorum won Iowa last time around, and Mike Huckabee won it the round before that. So, yeah.
Anyway! Let's see what ya got, Iowa caucus-goers!