But the biggest difference may have been a way in which Nevada was not like Iowa: The percentage of non-white voters.
As we've noted in the past, how much of a primary campaign shift to the left is a function of support for Bernie Sanders is hard to gauge. Seven out of every 10 Nevada caucus-goers identified as liberal, according to preliminary entrance poll data, and about a third identified as "very liberal" — nearly twice the number that did so in 2008. That year, 41 percent of caucus-goers identified themselves as moderates, substantially more than have in the early data this year. But Democrats nationally are more likely to identify as liberal than they were eight years ago.
It's also a group with whom Bernie Sanders usually does particularly well. On Saturday, though, Clinton battled Sanders nearly to a draw among liberal voters, while winning moderates handily. What's more, half of those who came out to caucus want a president who will continue the policies of Barack Obama.
How did Clinton do so well with liberals? Perhaps because of a way the electorate was very different than Iowa. There, Sanders appears to have narrowly won the vote among white voters, a group that made up about 6-in-10 voters. Among that other 40 percent, though, Clinton appears to have won by a wide margin. Preliminary entrance polls suggest that Sanders won Hispanic voters, which seems as though it may be belied by the vote in heavily Hispanic areas. Even a close race among Hispanics is bad news for Clinton nationally, given her reliance on non-white voters over the long term.
But if the Hispanic vote leaned toward Sanders or was close, but Clinton still won the non-white vote by a wide margin, that would suggest that Clinton's support among black voters was very big — the sort of margin that we assume is powering her lead in polls in South Carolina. And sure enough: Preliminary data suggest that black voters went three-to-one for Clinton.
As was the case in New Hampshire and Iowa, early data shows a wide gulf in vote preference by age. It seems that about as many voters under 45 caucused Saturday as did in 2008 — though this may change as more data comes in — and that group went heavily for Sanders, by a 3-to-1 margin. Among those 45 and over, Clinton got about 6 in 10 votes. It's not clear whether or not there was a big jump in younger voters in Nevada. In Iowa, the lack of such a jump may have cost Sanders the race.
Iowa and Nevada looked a lot alike as the election approached: A hard-fought caucus in which Clinton seemed to have an edge. Unlike in Iowa, Clinton did have an edge this time — that the electorate was less white than it was in the Hawkeye State. This is Clinton's proposition over the long term. A close race will tilt her way as more black voters go to the polls. Nevada appears to have proved that correct.