Are The NY Primary Polls Underestimating Sanders?

The April 19 New York primary is arguably one of the more important ones for Bernie Sanders, as he could continue his momentum and gain a significant portion of the state's 247 delegates. Early polls have shown Hillary Clinton leading Sanders by as much as 17 percent, according to Real Clear Politics' data. Yet Sanders has refused to accept these numbers. His support in New York City has been undeniable. At a rally in Brooklyn's Prospect Park on April 17, approximately 20,000 people showed up to hear him speak. Sanders has said the polls have been misleading, but is this true?

In an interview with NBC's Today, Sanders urged against the polls, which showed him at a double-digit loss behind Clinton. "Those are the public polls. The bottom line is, let's look at the real poll tomorrow. Generally speaking, polling has underestimated how we do in elections." For example, before the March 8 Michigan primary, early polls showed Clinton as the state's favorite and positioned her as the guaranteed winner of the primary. However, the Michigan polls were wrong, and Sanders, who was behind Clinton by 21 percent, pulled off a victory.

At every Sanders event, it is clear that his supporters believe in him and the momentum of his campaign. Similarly to his event in Brooklyn, approximately 27,000 people showed up to a Sanders rally in Washington Square Park. Sanders has made it clear that his supporters shouldn't believe the polling numbers, but should instead continue in their efforts to spread the revolutionary message. In his interview with Today, he talked about the political movement that he has created through his presidential campaign:

The main point is, I think, we have a message that's resonating all over this country. We have enthusiasm. We have energy. People understand it's too late for establishment politics and economics. They want real change in the country. They want leadership to stand up to the billionaire class. That’s what we are providing.

Sanders supporters have joined in his discussion of the misleading polling numbers, claiming that they are rigged and they're fully expecting an upset in the NY primary. One supporter, Daeha Ko, told The Daily Beast that the polls can easily be manipulated, specifically because they don't survey a sufficiently diverse group of people:

Yeah, polls can be misleading, if it’s only reaching 2 percent of the actual population, and those who take it don’t necessarily reflect the demographics of the polling group. It’s like anything in statistics, it can be manipulated by specific media outlets, or if the media outlet is reaching toward specific demographics.

On the day before the NY primary, Sanders trailed Clinton by nearly 13 percentage points. Clinton has also led Sanders in other categories that might be difficult for the Vermont senator to close the gap. Among women, Clinton led Sanders 60 percent to 37 percent, and among minorities, Clinton led 58 percent to 39 percent, according to a NBC/WSJ/Marist poll ahead of the NY primary. Moreover, Clinton has maintained a double-digit lead over Sanders in New York City, but the two candidates are nearly tied in upstate New York.

Now that Sanders has argued that the NY primary polls are misleading, perhaps even more of his supporters will vote to ensure that the polls are wrong. Despite Sanders' argument, the numbers leading up to the primary haven't been misleading, as they represent the data from the people surveyed, and those people support Clinton. However, that doesn't mean Sanders couldn't pull off another unexpected upset like he did in Michigan, which could show that the early polling numbers aren't always as accurate as we might think.