Of whether Iowans love him - a question a reporter had asked him hours earlier, when he was surrounded by television cameras outside a diner near Cedar Rapids - Christie told the crowd in Davenport: "I say heck, I don't know, we just met. But the early indications are good."
The New Jersey governor, who serves as chairman of the Republican Governors Association, spent a full day in Iowa, beginning with an RGA fund-raiser in the morning and ending by headlining the evening rally for Branstad.
In the middle of the day, Christie attended a fund-raiser for Kraig Paulsen, the speaker of Iowa's House. And he made time to swing through Marion, a town just outside Cedar Rapids, where he entered MJ's Restaurant to applause and friendly faces - at least some of them invited by Branstad's campaign.
"I just love him," said Jan Airy, 67, who said she told Christie he would do an "awesome job" as president.
Christie, taking questions from reporters outside the restaurant, said that it was "wonderful to get as much encouragement as I got inside here and in other places in Iowa today," but that his decision on running for president would be a "deeply personal" one.
Fielding questions from reporters, Christie criticized President Obama when asked about the recent surge in unaccompanied immigrant children trying to get into this country through the Mexican border.
"I have great empathy for that situation, but frankly, the administration has done an awful job in securing our border," Christie said.
Christie then brushed off a question on how he would address national immigration policy, saying, "I'm not going to discuss a complicated issue like immigration in a parking lot here in Marion."
Christie cited a lack of action by the federal government and said both parties were to blame - echoing his familiar criticism of a dysfunctional Washington.
In Davenport, Christie employed familiar talking points, including his challenges working with a legislature controlled by the opposite party - likening the decision of New Jersey voters to elect Democratic lawmakers and "a conservative Republican governor" to "13-year-old boys in the basement" performing a science experiment.
While "it's the governor's job to work with whoever the people send you," he said he has often had to exercise his executive powers, setting records for numbers of vetoes.
Christie also joked that he had to fly home Thursday night because the Legislature had met that day, and required "adult supervision."
"I have to get home to see what they were up to today," Christie said.
He did not mention that earlier Thursday in Trenton, lawmakers probing the George Washington Bridge scandal that has dogged his second term were questioning one of his top aides, Regina Egea, on why she didn't follow up on allegations that some of the lanes had been illegally closed.
Outside the state capitol in Des Moines earlier Thursday, Democrats bashed Christie's visit.
The cochair of the Democratic National Committee, former Minneapolis Mayor R.T. Rybak, referred to Christie as "filled with scandals" and attacked his record, citing slow job growth in New Jersey compared to other states.
In Davenport, Branstad introduced Christie as a leader who "has put his state back on track, balanced the budget without raising taxes."
Christie, in his remarks at the rally, told the crowd to go out and help elect Republicans.
Recalling a sermon he said he heard from a pastor in Albany about the value of "preaching to the choir," Christie said: "All of you are part of the Republican choir," who can spread their message to others in their state.
He also sounded a message of party unity: "Whatever differences we may have" as Republicans, Christie said, "they are very small compared to the differences we have with the other side."
Christie, who has raised record amounts of money as chairman of the RGA, said he would travel to 14 states between July and August to help elect Republicans.
His remarks in Davenport, which lasted about 20 minutes, were met with support from a crowd estimated by organizers at 250 to 300 people.
Christie "did not disappoint," said Randy Millam, 56, of Lowden.
A retired food-processing plant worker, Millam praised the New Jersey governor's "sense of humor" and "bluntness," though he said it's too soon to say whether he'd vote for Christie in 2016.
Others in the Marion restaurant were less reserved.
Airy, the 67-year-old woman who had told the governor he would do an "awesome job" in the White House, hugged him and said: "Good luck, honey. We'll be here for you."
"I'll be back," Christie told her.