Voters in Wisconsin went to the polls Tuesday in the first primary contest of April as polls are slated to close at 8 p.m. CT.
Democratic Sen. Bernie Sanders tries to keep his winning streak going while businessman and GOP front-runner Donald Trump tries to prevent his party's nomination from going to an open convention. Sanders has a substantial deficit in delegates compared to former Secretary of State Hillary Clinton, but his campaign has been buoyed in recent weeks by winning five of the last six state contests.
Recent polling in Wisconsin indicate that the race should be a close one between Clinton and Sanders on Tuesday. Even with big wins in recent states, Sanders trails Clinton by 263 in elected delegates. When superdelegates are included, Clinton leads by more than 700 delegates.
Because Democratic primaries are all proportional, Sanders is in need to win a state like Wisconsin by a large margin.
Meanwhile for the Republicans, Trump was once considered the favorite to win tonight's Wisconsin primary. His lead in the polls has eroded as Sen. Ted Cruz has a slight edge in the state going into election day. Trump enters Tuesday with a 737 to 475 delegate advantage over Cruz.
Trump needs to win 53.7 percent of the remaining delegates to clinch the nomination going into the convention. In order for Cruz to win the nomination outright, he needs to earn 82 percent of the remaining delegates.