Ms. Stevens, a moderate Michigan congresswoman backed by Democratic leaders in Washington and the leading pro-Israel super PAC, is aiming to win one of the party’s most important Senate primaries as a firm supporter of the Jewish state.

She does not believe there has been a genocide in Gaza. She supports maintaining U.S. military aid to Israel without conditions. And she makes no apology for receiving more than $28 million in advertising help from the nation’s leading pro-Israel super PAC, according to AdImpact, a media tracking firm. (Despite calling “for an end to dark money in this country” in an interview with The New York Times, she has received another $20 million in help from four other super PACs with undisclosed donors.)

The country also remains firmly in the news. Months into the war that President Trump and Prime Minister Benjamin Netanyahu of Israel started against Iran, fighting has flared up again, putting a fresh focus on America’s support for the Jewish state. On Wednesday, a House vote to eliminate U.S. aid to Israel split Democrats, with almost half of them supporting the move.

Now Ms. Stevens — who once said at a Hanukkah celebration that “Israel comes to me in my dreams” — is testing whether Democratic primary voters will embrace a pro-Israel candidate in a race where Middle East politics are a major issue.

“I’m not a wardrobe in search of a bedroom, shopping around policy positions,” she said. “You know, I’ve got an opponent who wants to make this race all about one matter. I’m not denying that it’s a matter we disagree on. I’m also not ignoring that there is real pain and rolling of Michiganders going on right now because of Donald Trump and his reckless bullcrap policies.”

She added, “I am not a Netanyahu apologist, all right?”

The Democratic establishment agrees with her. Senator Chuck Schumer of New York, the minority leader, has said she is more likely to win in November, and she has endorsements from Mr. Peters and other prominent Michigan Democrats.

A Michigan-born son of Egyptian immigrants, Dr. El-Sayed, 41, believes Israel has committed a genocide in Gaza. He would end American financial assistance to the country. He says Israel should not exist as an explicitly Jewish state. And if he wins, he says, he will aim to change the Democratic Party’s relationship with Israel.

Ms. Stevens, who holds far fewer campaign events that are open to the public than Dr. El-Sayed does, is not eager to discuss the subject of Israel. In April, she was booed at the Michigan Democratic Party convention over her pro-Israel stance. During a televised debate in late May, she dodged a question about what AIPAC would receive from her in return for its support.

While Dr. El-Sayed is planning rallies in Michigan this weekend with Senator Bernie Sanders of Vermont and Representative Alexandria Ocasio-Cortez of New York, Ms. Stevens’s allies are leaning on a popular Democrat who has not weighed in on the race: former President Barack Obama.

AIPAC, through its main super PAC, the United Democracy Project, has blanketed Michigan’s airwaves and screens with an ad showing Mr. Obama praising Ms. Stevens in 2018. In the ad, the former president calls Ms. Stevens, who served as chief of staff for the task force in charge of the 2009 bailout of the American auto industry, “a critical part of my team.”

The United Democracy Project has spent more than $6.2 million on that ad alone, according to AdImpact. That figure represents the highest ad purchase of the Senate race and is nearly twice the amount Dr. El-Sayed has allocated to advertising in total. None of the AIPAC-tied ads in the race mention Israel.