Ted Cruz, the Republican senator from Texas, won the first contest in the 2016 Republican presidential race Monday night, edging Donald Trump and and a stronger-than-expected Marco Rubio.
On the Democratic side, Hillary Clinton had an extremely narrow lead over Sen. Bernie Sanders with most of the precincts counted.
(Follow NPR's Iowa caucus coverage here.)
In his victory speech, Cruz said, "Tonight is a victory for the grassroots.... Tonight, Iowa has proclaimed to the world: Morning is coming."
Trump, who's held the top spot in surveys nationwide for months, underperformed his polls in Iowa. In his concession speech, he pointed to New Hampshire, site of the first primary next Tuesday.
Cruz carved out support in Iowa with his fiery conservatism and methodical outreach. Rubio is working to emerge as the clear favorite in his party's mainstream wing, which fears either Cruz or Trump would be disastrous in a general election matchup against the Democratic nominee.
Cruz is the top choice among very conservative caucus-goers in Iowa, while Trump is No. 1 among moderates. That's according to entrance poll interviews among those arriving at caucus sites conducted by Edison Research for The Associated Press and television networks.
Those who say they're somewhat conservative are split between Marco Rubio and Trump.
Half of GOP caucus-goers say they prefer a candidate from outside the political establishment, while 4 in 10 say they prefer someone with political experience.
More than 8 in 10 Democratic caucus-goers under 30 say they came to support Sanders on Monday night, as did nearly 6 in 10 of those between age 30 and 44.
But nearly 6 in 10 caucus-goers between age 45 and 64, and 7 in 10 of those 65 and over, came out to back Clinton.
That's according to entrance poll interviews with people arriving at their caucus sites.
The survey was conducted for The Associated Press and the television networks by Edison Research as voters arrived at 40 randomly selected sites for Democratic and Republican caucuses.