Former Vice President Joe Biden boasts a 24-point lead over Sen. Bernie Sanders (I-VT) going into Tuesday’s Michigan Democrat presidential primary contest, a poll released on Monday shows.

The Detriot Free Press survey, conducted EPIC-MRA, finds Biden leading Sanders 51 percent to 27 percent with likely Democrat primary voters. A win in Michigan would likely clinch the Democratic nomination for the former vice president, who regained his frontrunner status after impressive showings in South Carolina and Super Tuesday states. For the Vermont senator, the Great Lakes primary is a must-win with 125 delegates up for grabs, the biggest purse of the night. The candidates will also battle for delegates in Idaho, Mississippi, Missouri, North Dakota, and Washington.

“Something happened on Super Tuesday with (other) candidates getting out and people are all of a sudden questioning Bernie’s positions on issues,” EPIC-MRA pollster Bernie Porn said. “If anything, it may be low in terms of the percentage that Biden may get.”

“I believe the numbers,” he added.

However, the Free Press cautions:

Four years ago, the Free Press and EPIC-MRA reported results of a poll the weekend ahead of that year’s Democratic primary that showed Hillary Clinton with a 25-point lead on Sanders, the independent senator from Vermont. It was one of several late-breaking polls that showed the former secretary of state with such a lead, though calling on the Free Press’ poll concluded about a week before that election. Sanders went on to win a narrow 1.4-percentage-point victory in the primary, however, as younger voters, who overwhelmingly supported Sanders, came out in much greater numbers than expected and he ran up large vote totals outside metro Detroit compared with Clinton.

The poll, undertaken between March 4th and 6th, had 400 respondents and a margin of error plus or minus 4.9 percentage points.