DES MOINES, Iowa — As Iowans prepare to caucus on Monday, Democrats are facing a Bernie Sanders problem.

The 78-year-old Vermont socialist, who many in the party view as a risky bet in the general election against President Trump, could win both Iowa and New Hampshire. He’s been leading in recent Iowa polls, is drawing the largest and most passionate crowds, and has a deep organization that he’s been building since he nearly won the state four years ago. Should he win here, he’ll be the heavy favorite to take New Hampshire, which he won easily in 2016. Since the first caucuses in 1972, no Democrat who has won the first two states has ever lost the Democratic nomination.