On Friday and Saturday, Ms. Spartz hosted gatherings with constituents. And each day, she found herself in hostile territory.

She was booed, jeered and scolded over the Signal scandal at the Defense Department (she acknowledged that the Trump administration needed to do a “better job”), and the Homeland Security Department’s efforts to deport immigrants without due process (she declared that unauthorized immigrants were entitled to “no due process”). And she was accused of standing idly by as Elon Musk and his Department of Government Efficiency steered cuts to government services (she said the Trump administration was trying to stop fraud).

She faced chants of “Do your job!” At times, the events turned into shouting matches. Some of the exchanges have circulated widely on social media.

“You don’t have to scream,” she pleaded at a crowded town hall in Westfield, Ind., on Friday night. The event lasted for two interruption-filled hours.

“I understand there’s frustration,” she said at another point, as she tried to defend Mr. Musk and DOGE.

One person in the crowd told her she did not understand her role as an elected representative. “I understand my role very well,” she said. “That’s why I have these town halls.”

The crowd howled when she said she would not call for the resignation of Defense Secretary Pete Hegseth, who shared sensitive U.S. military plans on a Signal chat, apparently unaware that the editor in chief of The Atlantic had been inadvertently added.

Ms. Spartz, who was born in Soviet Ukraine, also faced questions about her position on U.S. aid for Ukraine. She said that she did not support the United States sending a “blank check to anyone” but that “Russia has been allowed to get away with too much.”

Outside the town hall on Friday, protesters who could not get inside chanted, “This is what democracy looks like.” Inside, Ms. Spartz threatened to stop hosting town halls.

But on Saturday, she was back at another one, in Muncie, Ind., facing down more angry voters.

“She’s not fulfilling her congressional duties and upholding the separation of powers,” said Josh Lowry, the chair of the Hamilton County Democrats, who led protests outside the town hall on Friday. “She’s selling out Hoosiers.”

Mr. Lowry said Republicans like Ms. Spartz had won elections in November by focusing on the cost of living, but have now instead joined in Mr. Trump’s campaign of “retribution.”

“They’re all worried about Trump endorsing an opponent” in a Republican primary election, Mr. Lowry said.

Republicans are also under pressure to hold onto their razor-thin majority in the House. This week, Mr. Trump announced that Representative Elise Stefanik of New York was withdrawing her bid to become the U.N. ambassador. The announcement highlighted worries among Mr. Trump and his party about their ability to win what should be safe Republican seats as Democrats have shown strength in special elections this year.

On Saturday, Ms. Spartz thanked everyone who had attended her town halls, but claimed that she had been targeted by people on the far left. She said that her staff members had been spat at and that a Trump supporter was punched outside the town hall on Saturday.

“The radical left is organizing to silence the truth at town halls, but we cannot let it happen,” she said in a statement. “It’s not pleasant, but I can handle their aggressive behavior.”

Christine Kassebnia, 62, a self-described swing voter who waited for more than two hours to get into the town hall on Friday, bristled at the suggestion that Ms. Spartz’s critics at the events were on the far left.

“These were not far-anything,” she said. “They were just people. And they’re upset.”