Sanders, Cruz Go Into Today's Primary With Clear Leads in Wisconsin Polls

In the most recent poll, however, released by Emerson on Monday, Sanders has jumped to an 8 point lead, while Cruz was up by 5 percent. Sanders is buoyed by the fact that the state has open primaries, in which independents can pick a party primary and vote in it. Sanders has much more support among independents than Clinton, according to virtually every poll. Wisconsin voters are also allowed to register right up until the primary, which is also thought to favor Sanders.

Ohio Gov. John Kasich, who is seemingly staying in the race for the possibility of a convention fight as he does not have a mathematical path to the nomination, has 21 percent support in the Badger State according to RCP's poll aggregator.

The Wisconsin contest is considered crucial to the four leading candidates. While Clinton still has a 228 delegate lead, Sanders has mounted victories in 6 of the last 7 contests. A Wisconsin victory for the Vermont Senator would further sharpen his argument that Democratic voters are not yet sold on the nomination of Clinton, while losing it to the front-runner means that a loss in the New York primary, where 247 delegates are up for grabs, could mean a total knockout to his chances.