Retired farm wife Phyllis Willis asks questions about water quality to Sen. Chuck Grassley (R-Iowa) during a town hall meeting in Garner, Iowa, on Feb. 21. (Rachel Mummey for The Washington Post)

GARNER, Iowa — In the politest possible way, Sen. Chuck Grassley (R-Iowa) asked his constituents to keep their voices down.

“I learned a long time ago that if I keep shut, I learn more,” Grassley said on Tuesday afternoon, to the crowd spilling out the doors of a community center meeting room. “If people just kind of respect other people speaking, it’ll help everybody to hear.”

It was Grassley’s second town hall of the day, the umpteenth of a political career that began with a 1958 race for state legislature. He wrote down each question as it was spoken to him — about the confirmation of Secretary of Education Betsy DeVos, about whether Congress would probe Russia’s election meddling, and whether he’d favor the impeachment of President Trump.

And he faced round after round of questions on the Affordable Care Act, from people who sometimes choked up as they described their specific, positive interactions with the law. After one woman emotionally described how her family would have been “destroyed” had the ACA’s subsidies not defrayed the cost of her husband’s illness, Grassley assured her that the law would not simply be repealed.

“There isn’t one piece of legislation put together yet,” he said. “If there is, it would be along the lines of giving the states some options of either staying under Obamacare or having some flexibility to do Medicaid.”

“But I don’t trust the state of Iowa,” she said. “That’s exactly how they privatized Medicaid. You’re asking us to pick up the in-between stuff, and we can only do it so long.”

“Why don’t you have a plan?” yelled another attendee, rows behind her.

“Who had the question about term limits?” said Grassley, plowing ahead with his list.

This week, during the first long recess of the new Congress, some Republicans were facing the first serious public blowback of their careers.

Grassley, seasoned and strategic, had several blowbacks to compare it to. In 2009, he’d been browbeaten by conservatives who demanded that he back away from Democrats who were trying to win his vote for the nascent ACA.

“We should not have a government plan that will pull the plug on Grandma,” he assured them that summer, signaling to Democrats that he would never come around.

This week, the chairman of the Senate Judiciary Committee is holding more public town halls than anyone else in his caucus. The attendees, largely opposed to the president and the Republican agenda, are arriving with hope that Grassley can be turned on any issue, and leaving with mixed signals.

The signals they liked the least came on Obamacare, where the lack of a coherent Republican plan to “replace” the law was a stumbling block. In Iowa Falls, after one man angrily demanded that Grassley give a straight answer — “don’t you dare give me those Washington talking points” — the senator suggested that the replacement needed to allow people currently covered to keep their plans.

“In every instance of the three or four programs that are floating around the House and Senate, every one but one would preserve the preexisting conditions [provision],” Grassley said. “It would preserve no personal limit on insurance that can be spent on one person in one year. It would allow a young person to stay on his parents’ insurance.”

At a news conference after the Garner town hall, Grassley said that “in November and December,” before activists began spilling into congressional offices and events, the party was more bullish on a fast replacement.

“There’s more of a consensus among Republicans now that you’ve got to be cautious,” he said.

The formats of the town halls have given Grassley more control over the audience than some of his colleagues. In Iowa Falls (pop. 5,217) and Garner (pop. 3,098), the senator arrived early at venues that each fit less than a hundred people. Constituents who arrived less than 30 minutes early were stuck in hallways; in Garner, they shouted, in vain, for the event to be taken outside. The senator did not use a microphone, which after some early static largely mean that critics spoke one at a time.

The result was sometimes a straight answer to a left-field question. When one Garner town hall attendee asked if Grassley would vote to impeach the president, the senator said that it wouldn’t be prudent to say.

“It has to start in the House of Representatives,” he said. “Let’s say it started. I would not want to give him my opinion on impeachment, because the Senate sits as a jury. We have to listen to the facts, the votes on the facts, just like a jury.”

By meeting some harsh questioners halfway, Grassley largely calmed down the rooms. But as in 2009, when tea partiers were armed with passages from the Constitution and reports from Fox News, Tuesday’s town hall attendees knew their material. A woman who wanted the president to release his tax returns got Grassley to admit that a 1924 law did allow Congress to request tax information that was not required by the Federal Election Commission.

“The Senate Finance Committee does that, but it never makes it public,” said Grassley. “So, I could see it, but you couldn’t.”

Some of the questions came from a larger frustration that Republicans, having won the election, were not accountable at all. In November, Trump’s surprising sweep of Iowa helped Grassley secure a seventh six-year term and helped Republicans take control of the state Senate for the first time in decades. In Des Moines, they’d set about dismantling a 44-year-old collective bargaining rule, part of a legislative agenda that progressive activists recognized from Republican Gov. Scott Walker’s Wisconsin.

In interviews, several attendees said they were worried about a new Republican proposal to ideologically balance public universities by requiring no political party to have more than a 10-point registration advantage among professors.

“That’s how it starts,” shouted one man in Garner as Grassley discussed immigration. “They come after the immigrants. Then they come after people who disagree! They come after professors if they’re Democrats!”

The conservatives at the town halls, victorious in November but outnumbered on Tuesday, had their suspicions about the crowds. In Iowa Falls, one wondered if the crowd had surged up from Des Moines, 90 minutes away. But interviews — and license plates, which in Iowa note which county the car was registered in — suggested that most of the crowds were local.

“It’s all legitimate,” Grassley said at Tuesday afternoon’s news conference. “If Hillary Clinton had won you’d see the same thing from other people.”

The people who were showing up had no shot at defeating Grassley; in November, they’d watched him win by a landslide. In around 20 conversations, most of Grassley’s critics admitted they had never previously gone to one of his town halls. Until this year, they had nothing terribly specific to ask him.

“With the ACA we pay $87 per month for a plan that covers me, my husband, and our 3-year-old,” said Sara Gilbert, 33, a farmer from Iowa Falls. “If they want to take that away, they’d better have something to replace it.”

But Gilbert had arrived for the 7:45 a.m. town hall just a few minutes early — long after the room was packed. She stood outside, unable to hear the senator’s answers.