Former President Donald Trump has a commanding lead ahead of his opponents in polling of the Iowa caucuses, but several factors could provide an unexpected result Monday night.

In the months leading up to the first-in-the-nation caucuses, Trump has strengthened his double-digit lead over competitors, with polls showing the support of more than half of Iowa Republicans. But the caucuses have yielded unpredictable results in the past, and the snowy forecast, same-day voter registration, and potential for persuasion could hand another candidate a victory.