ROCK RAPIDS, Iowa— Here at a town hall meeting of 126 people in this deep-red corner of the state, Sen. Charles E. Grassley was taking a beating from people who wanted to see him act to confirm Merrick Garland.

Attendees — some of them clearly activists from organized Democratic groups — repeatedly slammed the Senate Judiciary Committee chairman for refusing to hold hearings on Garland, President Obama’s nominee to replace the late Justice Antonin Scalia on the Supreme Court.

About 25 minutes into the meeting, a woman named Donna had heard enough. She rose to ask the Republican senator from Iowa — who is up for reelection to a seventh term in November — how long he’d been a farmer. Since 1959, Grassley answered.

“If you’re going to be a farmer, you have to have nerves of steel,” Donna said. “This is regarding the pressure you and many other elected officials are under from the president to do something about the Supreme Court. I hope you will stand firm.”

Cheers erupted from the crowd.

“Well, I will,” Grassley pledged.

Despite massive pressure from Democrats, Grassley is sticking steadfastly to his vow not to hold hearings or a confirmation vote on Garland before November’s elections, arguing that voters deserve to pick the person who will nominate the next high-court justice. As chairman of the Judiciary panel that considers Supreme Court nominations, Grassley is largely responsible for deciding whether to hold confirmation hearings.

So far, most of his GOP colleagues support his unwavering stance — only two, Sens. Mark Kirk (Ill.) and Susan Collins (Maine), favor hearings. Even if Senate Majority Leader Mitch McConnell (R-Ky.) never budges on hearings, Grassley could theoretically change his mind and advocate for them.

For Grassley, 82, the political calculus is pretty simple: He’d much rather take heat from Democrats than Republicans in a wildly unpredictable election year in which Donald Trump may top the ballot in this swing state. Conservatives have posed a problem for Grassley in the past. Six years ago, when he was last up for reelection, he faced an uprising from the right for trying to craft a bipartisan health-care plan with then-Sen. Max Baucus (D-Mont.).

Grassley abandoned those plans in summer 2009 (although he blamed an “artificial deadline” for a deal set by the White House) and, apparently, is not keen on facing another conservative insurrection in 2016 — this time about the Supreme Court.

“I’m not surprised with the pressure I’m getting now. But it’s a lot more fun to have it come from the Democrats than it is from Republicans,” Grassley said Tuesday as he headed for his car at the end of one of nine meetings with Iowa voters in just two days.

“I’ve got to be consistent” on my no-hearing-no-vote stance, he said.

Consistency is what McConnell was striving for when he instantly declared that Senate Republicans would not hold confirmation hearings or a floor vote on Obama’s nominee to the high court. Most Republicans quickly fell in line, including Grassley. And Grassley held doggedly to his position under a barrage of questioning at several public events here last week.

“When you have a lame duck president, during the last year, a [Supreme Court] appointment should go over to a new president,” Grassley said, repeating a phrase he used at least a dozen times in recent days.

Some wonder why McConnell chose to draw such a bright-red line in the court fight, arguing he is endangering an already fragile Senate majority in which a net gain of just three seats would hand control to Democrats. But Grassley’s message at home — met with applause and nods from his conservative constituents — suggests why compromise from Republican senators up for reelection is unlikely: They are more worried about blowback from their base than weathering the wrath of Democrats or independents.

“Conservative groups are very much behind what we’re trying to do,” Grassley said following a town hall event at Northwestern College in Orange City. “They figure that if this president appoints somebody, you’re going to have a lot of negative freedom-of-religion decisions, a lot of negative gun decisions, a lot of negative political-speech decisions. So we want to make sure the court doesn’t veer to the left.”

The campaign to bolster Grassley has already begun. The anti-abortion rights group Susan B. Anthony List is buying television and radio ads and the Judicial Crisis Network has spent over $750,000 on similar campaigns backing Grassley’s position.

“Sen. Grassley needs us to match the intensity of the other side right now,” said Susan B. Anthony List President Marjorie Dannenfelser. “We will continue this encouragement for the coming weeks and months so that Sen. Grassley knows we stand with him.”

On the other side, liberal group Justice Not Politics, led by a group of female Iowa politicians, intends to spend more than $100,000 on ads across Iowa that urge voters to call Grassley and demand he hold hearings.

But such moves may not change the minds of Iowans, who reelected Grassley with 65 percent of the vote in 2010. Chris McGowan, president of the Siouxland Chamber of Commerce, says the senator is seen as independent and thoughtful, but that does not mean most Republican voters expect him to back Garland.

“Maybe there are some forces on the left that want to see Grassley’s independent streak at this time and he’s not demonstrating it for them,” McGowan said. “[Voters] know that he’s thoughtful and he’s deliberative and they respect that,’” he added. “He’s very, very likely to be reelected, and Iowans know what to expect from him.”

Democrats clearly hope that Grassley — with his longstanding reputation for bipartisanship and civility — will be damaged by his uncompromising stance on Garland. He has no primary opponent, while Democrats are engaged in a four-way contest on June 7 to pick his challenger.

The Supreme Court fight prompted Lt. Gov. Patty Judge, who could potentially deliver the incumbent’s most viable challenge in years, to jump into the Democratic primary just weeks before the filing deadline.

Judge traveled to Washington to meet with Senate Minority Leader Harry M. Reid (D-Nev.) and have lunch with Senate Democrats less than one week after she announced her bid, and party operatives have quickly mobilized to bolster her campaign. She is hoping to convince moderate Republicans and undecided voters that senators have abandoned their sense of civic duty for obstructionism and that Grassley can no longer be trusted to be independent.

“This is not the Chuck Grassley that we knew a few years ago,” Judge said in an interview. “He has managed to establish around himself an aura of incivility. He has been able to attract an independent voter and in fact some Democratic voters. I think that day is over.”

And there undoubtedly will be plenty of pressure from Democrats for Grassley to change his mind.

Democratic-leaning groups Progress Iowa, Why Courts Matter and NARAL-Pro Choice rallied supporters via email in the days ahead of Grassley’s visit home, and pro-Garland activists showed up to each of the three public events listed on the senator’s website, as well as several private ones held in between.

A man dressed as Benjamin Franklin was one such activist who last week followed Grassley from town to town. Each time Franklin, also known as John Robinson of Des Moines, politely raised his hand. And each time Grassley listened to a version of the same question: Why won’t he just hold hearings on Obama’s nominee for the Supreme Court?

“Aren’t you concerned that it will be two full terms before the Supreme Court can make a decisive decision?” Robinson said.

It was the second question at a meeting in Ocheyedan and the second one about the Supreme Court. More than 60 people packed into the small senior’s center in this rural town, population 490, creating a tiny spectacle along the town’s main intersection.

Grassley’s answer was always consistent. “When you have a lame-duck president, during the last year, a [Supreme Court] appointment should go over to the new president to make the choice,” Grassley said, repeating a phrase he used at least a dozen times last week.

If Democrats want to make this a real race, they will have to win voters like Lorna Horn, 80, who attended a Grassley town hall in Rock Rapids. “The president now was chosen by the people, so I think it gives us a better reputation if we at least allow something to be done,” Horn said.

Horn has voted for Democrats and Republicans in the past, and although she’s on the fence this year, she said she’s starting to doubt that she can back Grassley this year.

“They have to work together in Washington — that’s why they’re there,” she said.

But Grassley is relying on the Republicans who have supported him in the past, hoping they know he’s the same guy who has visited all 99 Iowa counties every year since he was first elected 26 years ago.

Phillip Stracke, who has run a farm for 44 years, said he is still forming an opinion about whether Grassley should hold hearings.

But he was swayed by the senator’s argument that the people should make the ultimate decision. “In the Supreme Court, they’re trying to make law and have made law. That’s not their job,” Stracke said. “When it comes to the court, it isn’t we the people and I don’t get to vote on them. I get to vote . . .  on Congress and the president.”