There are plenty of explanations for what happened in the Michigan Senate Democratic primary, where Dr. Abdul El-Sayed, a progressive, was declared the victor over Rep. Haley Stevens, a moderate, by a razor-thin margin of one percent.

For starters, he was the outsider, a former public health official talking about the fundamental economic issues, while she was Senate Minority Leader Chuck Schumer's second choice (after Gov. Gretchen Whitmer) for the seat. He was, according to observers, the better communicator, the better orator, connecting on issues of affordability while she was expounding on her love for Michigan. He worked harder. He started campaigning well over a year ago and did some 500 public events against a candidate who stayed mostly out of the public eye and dodged tough questions.

And the polls were wrong, as usual. The polls were projecting a double-digit El-Sayed victory. That didn't happen. It turned into a cliffhanger, and El-Sayed only won by a razor-thin margin. So in that sense, as is always true of very close races, anything could have made the difference.

But there are certain facts coming out of Michigan that cannot be denied. Rep. Stevens was supported by some $60 million in outside money, including more than $30 million from the American Israel Public Affairs Committee. That's AIPAC, for short, the pro-Israel lobby that used to wield enormous clout in Washington and in national politics. Her extraordinary support from AIPAC became an issue in the campaign, as did her opponent's stance on Israel.

Dr. El-Sayed is the sort of candidate that AIPAC exists to defeat. He believes that Israel committed genocide in Gaza. He has pledged to cut U.S. military aid to Israel. And, according to The New York Times, he has said he does not believe Israel should exist as an explicitly Jewish state. Throughout the campaign, El-Sayed attacked Stevens for her pro-Israel position, and said he hoped to go to Washington to influence policy on Israel, especially among the party's 2028 hopefuls.

AIPAC spent more money, according to the Times, trying to beat El-Sayed than any outside group has in a primary this year. They put $30-plus million on the scale and became a much-debated issue in the campaign for doing so. The message to other candidates is clear: AIPAC money comes with a price. Did it hurt Stevens more than it helped her? While apologists for AIPAC may spin that even with prevailing winds against them, they almost pulled it off, the fact of the matter is that they didn't pull it off. They lost.

A few years ago, there would have been no place in the Democratic Party for a candidate like El-Sayed. His views on Palestine would have been unacceptable. He would not have been given a speaking role at a national convention. As I write this, the party is unifying behind him to give him a speaking and voting role in the U.S. Senate.

As the polls have measured, accurately, public opinion on Israel has shifted dramatically, and negatively. Some of us continue, albeit with difficulty, to draw a line between our support for Israel and our opposition to its current government, but most people don't. They don't view Israel through the Holocaust-tinged glasses of my generation. We know this. AIPAC has to know this. The lesson of Michigan cannot be that they just needed a little more money. The message is not working.

Susan Estrich is a celebrated feminist legal scholar, the first female president of the Harvard Law Review, and the first woman to run a U.S. presidential campaign. She has written eight books.