A poll released Wednesday morning by Iowa State University shows Bernie Sanders holding a five-point lead over Elizabeth Warren, and topping the entire primary field when second choices are considered (a key factor in the caucuses, where a re-alignment takes place after the first count in which undecided voters and supporters of campaigns that fall under the 15% viability mark can choose a new candidate). This is only the latest poll showing Sanders with an advantage, and in the Real Clear Politics list of Iowa polls, it shows the Senator with a lead in four of the last five. That complements his lead in the last six New Hampshire polls. In Nevada, though Biden has routinely led Sanders with slight margins with rare exceptions, Five Thirty Eight is now projecting that the margin is close enough that Sanders will win Nevada, perhaps based on potential momentum from the first two battles.

Biden will certainly win the fourth primary in South Carolina, but then Super Tuesday comes, and with it the massive California primary that Sanders, too, is expected to win.

Five days is a long time in campaign politics, and a lot could change between now and Iowa, and it’s worth noting that the margins are razor-thin in every state but South Carolina. If you were a gambler and you wanted to pick the candidate who would definitely win one of the first four, you’d pick Biden and his sure-thing fallback in South Carolina. But for the first time, sites like Five Thirty Eight are considering Sanders the favorite in the first three states, and that’s a status he’s never experienced.