(Bloomberg) -- Joe Biden returned to the campaign trail Wednesday with a defense of the Affordable Care Act, consciously drawing a contrast with other Democratic presidential hopefuls after spending weeks focused almost exclusively on President Donald Trump.“I fundamentally disagree with anyone who says scrap Obamacare,” the former vice president told voters in Waterloo, Iowa, at his first public appearance since last Thursday’s primary debate. “I’m against any Republican who wants to scrap it, I’m against any Democrat who wants to scrap it.”Biden’s comments touched on a divide within the Democratic Party that was on view during both nights of last week’s debates in Miami – over whether to end the existing private insurance system that covers millions of Americans and replace it with Medicare for All.“I’m going to be very blunt with you: it’s going to be a debate among us all in this race,” he said, adding that there are “a lot of good people running.”The opponents closest to Biden in the polls – Vermont Senator Bernie Sanders, Senator Kamala Harris of California and Massachusetts Senator Elizabeth Warren – back Medicare for All, which would eventually include the elimination of private insurance that remains popular with many voters.Biden has not yet rolled out his full health care plan, but suggested Wednesday that he would favor a hybrid public-private system that could help the uninsured get coverage.“We can’t start over. There’s no time to start over in my view,” he said. “Building on what we’ve got, not starting over. Allowing people to keep their employer-based insurance or their private insurance or any insurance they have if they want. But if they don’t, allowing them the ability to buy into a public option, a health care plan like Medicare.”He pointed out that many presidents before Barack Obama had tried to pass a health care bill and not succeeded. “We have to finish the job and make health care a right not a privilege,” he said. Biden’s shift to a more direct comparison with other candidates for the Democratic nomination comes after he stumbled last week when facing an attack from Harris on his opposition to federally mandated busing to desegregate schools during the 1970s and has since seen his poll numbers drop.A Quinnipiac national poll released Tuesday found Biden slipping to 22%, just 2 percentage points ahead of Harris at 20%. Warren was next with 14% then Sanders with 13%. A CNN national poll found Biden slipping 10 percentage points in one month — to 22%. Behind him was Harris with 17%, 9 percentage points higher than in CNN’s previous poll, and Warren with 15%, an 8-percentage-point gain, and Sanders with 14%, a 4-percentage-point drop.Biden’s campaign said Wednesday that it raised $21.5 million in the second quarter, second to Mayor Pete Buttigieg of South Bend, Indiana, who took in $24.8 million.Biden’s team was quick to note that he entered the race on April 25, nearly a month into the quarter, meaning that he took in more per day than any other candidate. Sanders said that his campaign raised $18 million during the second quarter. Harris and Warren have not yet disclosed their fundraising totals.On Thursday, Biden plans to march in a July 4 parade in Independence, Iowa, and to take in an Iowa Cubs game in Des Moines, the state capital.(Updates with additional quote, in eighth paragraph. An earlier version corrected the day that Biden spoke, in sixth paragraph.)To contact the reporter on this story: Jennifer Epstein in Washington at jepstein32@bloomberg.netTo contact the editors responsible for this story: Alex Wayne at awayne3@bloomberg.net, John Harney, Max BerleyFor more articles like this, please visit us at bloomberg.com©2019 Bloomberg L.P.