But then he went home to Iowa, and the message changed. In a series of tough town halls, he fueled fears of death panels and benefits for illegal immigrants. He suggested the White House would push a purely partisan bill. And he proclaimed himself an outsider in health care negotiations.
"I'm not walking away from the table, I'm being pushed away from the table," Grassley said in Afton, Iowa, warning that Democrats might go it alone on health care.
Grassley's Iowa road show shows just why Democrats feared this August recess.
If the Democrats lose Grassley, the top Republican negotiator on the Senate Finance Committee, they likely lose any hope of a bipartisan bill. Even worse, if Grassley bails, then conservative Democrats like Ben Nelson may follow.
While Grassley has always criticized the process in the Senate, his fresh criticisms, before the home state crowd, are magnified as contentious town hall scenes are repeated across the country. And if the August unrest has spooked a safe, respected senior senator like Grassley, it can't be good sign for the dozens of much more vulnerable moderates from both parties, who worry that the wrong vote on health care could cost them the job next year.
The White House effort to woo Grassley in recent months shows just how critical his support is for the appearance of a bipartisan effort. In addition to his White House lunch with a small group of senators before recess, Grassley had a series of personal conversations with President Barack Obama about the legislation. He's been at the table every day, hour after hour, trying to negotiate a deal.
But in four packed public events this week in Iowa, Grassley repeatedly distanced himself from the Democratic plans to reform the health care system.
"We don't have any bill. We may never have a bill," Grassley said, offering few indications that he expected to reach a deal with Democrats.
"Even though I'm talking, and have been for months, with people in my party and people in the Democratic Party," Grassley told town hall attendees, "things could fall apart."
Grassley says that the outraged reaction at town hall events hasn't changed his message. In fact, even as he dealt with the fired up crowds in Iowa this week, he has held multiple conference calls with his Washington colleagues, including Finance Committee Chairman Max Baucus (D-Mont.).
"There's nothing final until the whole thing is final," he told reporters on Wednesday afternoon. "What we're doing is, we're talking."
But he noted that his town hall meetings on health have drawn three times as many attendees as past events — a dramatic increase given that Grassley has held 2,846 town halls over his career.
"The message I got is that people are very definitely opposed to any piece of legislation that would even lead to a take-over of health care," he said.
Grassley, a five-term senator up for reelection in 2010, holds a relatively safe seat. But there's always the danger that Iowa's influential Republican base, outraged over the health care plans, could turn on him. Conservative voters still hold great power in the Midwestern swing state: In the 2008 Republican primary, huge turnout from social conservatives helped former Arkansas governor Mike Huckabee win the state.
Multiply that party-base angst by several times, and you have the central problem for health reform: Vulnerable lawmakers are getting hammered back home this month.
To avoid those attacks from the right, Grassley must walk a fine line between his role as an influential health care negotiator in the Senate Finance committee and his home base.
The Iowa town hall attendees didn't hide the political price they could exact on lawmakers over health care reform.
"I'm a conservative, and what we expect is for you to fight for us," shouted a questioner at a town hall in Adel, Iowa. "Every senator, Democrat or Republican, that votes for this bill — we will vote you out."
Their skepticism about Grassley's Senate insider role intensified after Obama praised Grassley during a Tuesday town hall event as one of his "Republican friends on Capitol Hill who are sincerely trying to figure out if they can find a health care bill that works."
The compliment didn't win him any applause from the hundreds of conservatives who came to question him the following day.
"The president did single you out yesterday as being one of the people willing to talk about various provisions," said Deb Etcheson at a meeting in Afton, Iowa.
"One of the things in this whole controversy that scares me so much is that when you hear the Obama sound bites his advocacy of the current health insurance, etc., sounds very much like you," said another town hall participant.
Grassley tried to distance himself from the inside-the Beltway reputation as a dealmaker and negotiator.
"I feel a little bit like the boy sticking his finger in the dike trying to stop the ocean from coming in," he said of his work with the Senate Finance committee. "I have an opportunity to give the grass roots of America to speak up as you see every day on television."
He stressed his staunch opposition to a government-run plan, including a public option for insurance coverage, a key aspect of the president's agenda. It's becoming clear that no public option is going to come out of the Senate Finance Committee with Grassley's support.
Grassley also didn't go out of his way to dismiss concerns about end of life counseling in one version of the bill.
"With all the other fears people have and what they do in England then you get the idea that somebody is going to decide grandma lived too long," said Grassley. "You understand why you get it."
Grassley was on a roll with his partisan base at this point, even as health reform proponents asked him to watch the rhetoric.
Cheri Heiland, a questioner at a town hall in Panora, Iowa asked Grassley to "denounce the tactics that are getting thrown at the Democrats."
"You know there is nothing in the House bill that will require any elderly person to stand before a committee and decide whether or not they are going to live or die," she chided, as the roughly 200-person crowded booed.
Grassley's carefully navigated the issue.
"I wanted to make sure that people understood that I was not for rationing and having a government bureaucrat decide when Grandma's going to die," he later told reporters.
But that type of August sidestepping will be a lot harder when he returns to the Senate conference table come September.
Carrie Budoff Brown contributed to this story.