DETROIT, Michigan —With all eyes fixed on Michigan’s contentious Democratic primary Tuesday, it could be Mississippi — a state whose outcome is nearly a forgone conclusion — that has a bigger impact on the nuts and bolts of winning the Democratic nomination.

Michigan is in many ways a more consequential contest than Mississippi, thanks to its size, diversity, and industrial economy. Both campaigns have a lot to prove here. And both campaigns say they expect a much closer race than the polls showing a double-digit Clinton lead suggest, though that could be spin.

Mississippi, on the other hand, has less than a third as many delegates as Michigan (41 versus 147) and no one doubts that former Secretary of State Hillary Clinton will beat Sen. Bernie Sanders there. But in one key way, Mississippi could prove more important.

Since delegates are awarded proportionately in the Democratic nominating process, a Clinton landslide in Mississippi could impact the overall delegate race more than a narrow win for Sanders in Michigan, despite its size and importance.

In the proportional system, margins often matter more than wins. A narrow win splits delegates roughly evenly, giving the winner only a handful more than delegates than the loser. But a big win awards a big prize.

For instance, in the eight states Sanders has won, he has netted a total of 76 delegates (Sanders’ delegates minus Clinton’s). Clinton, meanwhile, has netted 129 delegates in four states alone — South Carolina, Georgia, Alabama, and Louisiana. And depending on the margin in Mississippi tonight, Clinton could end up doubling Sanders’ delegate net in Deep South states alone.

Sanders has not bothered competing in Mississippi, given Clinton’s enormous margins among African-Americans. “Today begins the most important seven-day stretch of our campaign: tonight, Michigan votes. Next week, Illinois, Ohio, Florida, Missouri, and North Carolina follow suit,” Sanders said in a fundraising email sent to supporters Tuesday, omitting the primary in Mississippi today.

Top Sanders aides have noted there are no more Southern states left on the map after Tuesday, and campaign manager Jeff Weaver quipped that Clinton is a “regional candidate” who can’t win outside the South.

Even if that were true, Clinton has banked so many delegates in the South that narrow wins for Sanders in future contests may not be enough to make up the delegate count.