The big question in Iowa this year has been how many new caucus participants will show up. Both Donald Trump in the Republican contest and Bernie Sanders in the Democratic race were counting on a strong turnout from first-time caucus-goers.
In the 2008 Democratic caucuses, 57 percent attended their first presidential caucus. This year that number has dropped to 42 percent. Sanders was counting on these new voters to propel him to victory. He's winning six out of 10 of these new voters. The question is whether enough of them showed up tonight.
Related: Up-to-the-minute Iowa caucus results
On the Republican side, 46 percent of caucus-goers are first-time participants. This is larger than their 38 percent share in 2012, but perhaps not quite as strong a showing as some observers had expected. Trump is winning nearly a third of these voters, while Ted Cruz and Marco Rubio each claim about one-in-five of this group.