DES MOINES, Iowa (Reuters) - Joe Biden is still the front-runner in the Democratic presidential race, but the crown is slipping.

FILE PHOTO: Democratic 2020 U.S. presidential candidate and former Vice President Joe Biden greets supporters at the Independence Day parade in Independence, Iowa, U.S., July 4, 2019. REUTERS/Brenna Norman

On a two-day holiday visit to Iowa, the state that kicks off the White House nominating fight in seven months, Biden was greeted by new polls showing his lead narrowing in the state and nationally after a wobbly performance in last week’s first debate.

Biden’s halting response to a bruising debate attack on racial issues from rival Kamala Harris, a black U.S. senator from California, has some Democrats in Iowa rethinking their support for the former vice president.

“The debate changed things for me quite a bit,” said Sheldon Ohringer, 62, a West Des Moines Democrat who had been leaning toward Biden but is now considering Harris and several other candidates.

“I was really surprised Biden wasn’t prepared for some of those attacks. He didn’t handle it,” he said.

The tepid debate performance inspired little confidence among Iowa Democrats who are evaluating which Democratic contender is best suited to go toe-to-toe with Republican Donald Trump in the 2020 election.

And it also reinforced persistent questions about one of Biden’s biggest vulnerabilities -- whether at age 76 he is too old for the game.

“I had been wavering on Biden, but the debate took him off my list,” said Karen Wiesemann, 74, of West Des Moines, who now, too, is taking a fresh look at Harris and some others. “It’s time for new leadership.”

Biden has been on the defensive since the confrontation with Harris, who criticized his opposition to federally mandated busing to integrate schools in the 1970s and his willingness to work with segregationist senators.

Polls show Harris, who also was in Iowa around the July 4th holiday, has surged in the Democratic race since she confronted him.

In Iowa, a Suffolk University/USA TODAY poll taken after the debate showed Biden still leading, but Harris jumping into second place ahead of rivals Elizabeth Warren and Bernie Sanders, both U.S. senators.

A national Reuters/Ipsos poll also found Biden still ahead, but his support was down 8 percentage points from a similar poll earlier in June. Among blacks, support for Biden was cut in half.

A CNN national poll showed Biden’s support dropping 10 points since May.

“STILL WAY AHEAD”

Talking to reporters after marching in a July 4th parade in the small town of Independence, Biden shrugged off concerns about the polls and said he was happy with his debate performance.

“I’m still way ahead,” he said. “If you notice, I’m the guy everybody’s talking about.”

But Biden also seemed anxious to move beyond busing and other explorations of his lengthy public record, saying it could easily be distorted in the short sound-bites of a presidential debate.

In an interview with CNN that aired on Friday, he said he was not prepared for the attack from Harris, particularly on issues of race, given his record fighting for civil rights.

“I was prepared for them to come after me, but I wasn’t prepared for the person coming at me the way she came at me,” Biden told CNN.

He also tried to reassure Democrats concerned about his ability to stand up to Trump. “He’s the bully that I knew my whole life. He’s the bully that I’ve always stood up to,” he said.

Several Democrats who came to a picnic in West Des Moines to listen to Harris said they were excited at the possibility she could wound Trump the way she did Biden.

“I was impressed by her debate performance, she certainly could stand up to Trump - she’s forceful, but she stays calm. I don’t think she would be baited into a shouting match,” said Lisa Earles, 37, of Clive, who was wearing an “Iowa Stands With Refugees” t-shirt.

Talking to reporters after the picnic, Harris played down the polls.

“The fact that we are seeing momentum grow across the country is something I’m very proud of,” she said. “But there is still a lot of work to do.”

After two failed runs for the presidency, in 1988 and 2008, and eight years as vice president under Barack Obama, Biden has plenty of history in Iowa, if not success. He dropped out before Iowa’s nominating contest in 1988, and he finished fifth with less than 1% of the vote in Iowa in 2008.

But some Democrats said there was still plenty of time for Biden to recover.

“The debate shook things up, but I think it’s temporary. He won’t get caught flat-footed again,” said Dan Callahan, chairman of the Buchanan County Democratic Party.

Mary Loots, 67, a Democrat in West Des Moines, said she had plenty of respect for Biden but was considering Harris after the debate. Biden will have to improve his performance to stay in the race, she said.

“He seems weaker than in the past. One debate doesn’t kill a candidate, but if there is a second one like that he is in trouble,” she said.