Harris Says Trump Will Repeal Obamacare. Trump Now Claims He’ll Make It ‘Better.’

Vice President Kamala Harris and her running mate Tim Walz, the Minnesota governor, have quickly made the Affordable Care Act central to their campaign, raising the specter of another Republican repeal effort next year if former President Donald J. Trump wins the White House.

“If Donald Trump gets the chance, he will end the Affordable Care Act and take us back to a time when insurance companies had the power to deny people with pre-existing conditions,” Ms. Harris said at a rally in Philadelphia last week as she introduced Mr. Walz as her running mate. “You remember what that was like?”

The next day, Mr. Walz said at a rally in Detroit that Mr. Trump would continue trying to undermine the 2010 health law because “he doesn’t care.”

But so far they are battling an opponent without a position.

Missing from the campaign this year is an organized effort against the Affordable Care Act by Republicans, who have tried and failed repeatedly to repeal the law. Mr. Trump threatened yet another repeal effort in November, but he walked his comments back in the spring, saying without specifics that he would make the health law “much better.”

“President Trump is not running to terminate the Affordable Care Act,” Karoline Leavitt, a Trump campaign spokeswoman, said in a statement. “He is running to make health care actually affordable.”