Ted Cruz won the Iowa caucuses by winning a few key demographics (The Washington Post)

Powered by enormous support from very conservative voters, Ted Cruz surged past expectations to capture a victory in the Iowa caucuses on Monday night.

Cruz earned the support of 4 in 10 “very conservative” voters in the state, a group which made up 40 percent of the electorate according to preliminary entrance poll data. Cruz was also backed by 1 out of every 3 evangelical voters -- an important victory in a group that accounted for nearly two-thirds of the electorate.

Donald Trump may have been hampered by two unexpected factors: Weaker than expected performance among new voters and a late surge by Marco Rubio. In the last Des Moines Register/Bloomberg poll in Iowa, Trump led Cruz among first-time caucus-goers by 16 points. On Monday night, Trump’s margin among this group was closer to half that.

Rubio earned about as much support from new voters as did Cruz, and was the preferred candidate of about 3 in 10 Iowa Republicans who made up their minds in the last week.


TRUMP FADES WHILE RUBIO CLOSES STRONG

Fully 45 percent of Republican caucus-goers report making their final decision in the week before the caucuses, and the entrance poll shows Rubio performed strongly with. Nearly 3 in 10 of final-week deciders supported Rubio; he garnered about as much support among those deciding in January, but only about 1 in 10 of those who decided earlier than that backed Rubio.

Equally stark was Trump’s weakness among late-deciding voters. Just 14 percent of Republicans who decided in the final week supported Trump, compared with 23 percent of those who decided earlier in January and 40 percent who made their decision in December or earlier.


LARGE EVANGELICAL TURNOUT

Cruz leads among evangelical Christians, who made up 64 percent of Republican caucus-goers, up 7 points from 2012. Cruz garnered about one-third of the evangelical vote, compared with just over 2 in 10 apiece for Rubio and Trump. Trump’s barely topped Rubio among non-evangelical Republicans (29 to 26 percent), though they made up fewer than 4 in 10 caucus-goers, lower than 2012 or 2008.

CRUZ DOMINATED TRUMP AMONG STRONG CONSERVATIVES

Preliminary entrance poll results show Ted Cruz dominated among Republicans who identify as “very conservative,” a group which made up about 4 in 10 caucus-goers. Cruz garnered over 40 percent of their support, doubling Trump at about 2 in 10 and Rubio slightly below that level. The other large ideological group in the contest were “somewhat conservative” Republicans, a large but critical group across Republican contests. Cruz won 19 percent among this group while Trump won 24 percent and Rubio won 29 percent. Trump performed best with moderates (garnering 34 percent), but they accounted for just 14 percent of the GOP electorate.

FIRST-TIMERS SHOW UP, BUT NOT ALL FOR TRUMP

Record turnout in the Republican contest was reflected in the many newcomers engaging in the caucuses, and 45 percent of Republicans saying it was their first time participating, up from 38 percent in 2012. But only about 3 in 10 of these newer voters said they showed up to support Trump -- just over 1 in 5 supported Cruz and a similar number backed Rubio. Among repeat caucus-goers, who made up 55 percent majority of voters, Cruz topped Rubio 32-24, while 19 percent backed Trump.

These are preliminary results from a caucus poll of voters as they entered randomly selected caucus voting places in Iowa on Feb. 1, 2016. The Republican entrance poll results are based on 1,794 interviews, while Democrats are based on 1,660 interviews. The poll was conducted by Edison Media Research for National Election Pool, The Washington Post and other media organizations. The results for typical characteristics have a margin of sampling error of plus or minus four percentage points.