There are no doubt a lot of reasons that Donald Trump’s expected victory in the Iowa caucuses turned into a loss. Monmouth University went back and talked to voters it had polled shortly before the caucuses began and found a strong shift against Trump shortly before voting began. Combined with Trump’s paltry, I’m-sure-it-will-happen turnout effort — and Ted Cruz’s robust one — Trump’s slight lead became a relatively big loss.

New Hampshire is different, for a lot of reasons. It’s different because the electorate is more moderate, which plays to Trump’s strengths. It’s different because Cruz locked down the substantial conservative voting bloc in Iowa, but the moderate vote in New Hampshire is split among a number of establishment hopefuls. And it’s different because Trump has led in the state by a lot, for a long time.

The University of Massachusetts-Lowell and 7 News have been tracking how New Hampshire Republicans feel about the field all week. In the aftermath of the caucuses, Marco Rubio saw a quick surge of support, thanks to his unexpectedly good third-place finish in Iowa. That seems to have flattened out now, though, and Trump’s lead in the poll is still substantial.

What’s more, Trump has the smallest percentage of supporters who say they might change their minds. Rubio, after that initial surge, has seen his base of support start to waver.

But remember: Nearly half of the Republicans who voted in the state’s primary in 2012 made up their minds about who to back within the last few days before the voting began. That’s the context for Saturday night’s debate; history shows that a lot of people who come out to vote are still thinking over their decision.

For Trump to lose, two things need to happen. First, the portion of his support that says they might change their minds would have to change their minds. Even if he lost all of that support, though — a fifth of his base — he’s still winning. Second, a lot of the people who are firmly committed to backing Trump would have to stay home. That happened in Iowa. Trump’s campaign has had a week to try to ensure that its turnout system is up to par, which helps. (When I visited earlier this month, not much was going on.)

There’s one other thing working against Trump in the Granite State: People think he’s going to win by a mile. And there’s not much incentive to going out into the cold to vote for a guy who you assume is going to win anyway. Trump’s enthusiasm for polls showing him way ahead is a good way to get applause. It’s not a good way to get turnout.