DORAL, Fla. — Suddenly armed with fresh political ammunition, Donald Trump and anxious Republicans seized on spiking health care costs Tuesday in a final-days effort to spark election momentum.

The Republican presidential nominee, trekking across must-win Florida, insisted “Obamacare is just blowing up” after the government projected sharp cost increases for President Barack Obama's signature health care law.

Democrat Hillary Clinton, fighting to block Trump in the same battleground state, has vowed to preserve insurance for the millions of Americans covered under the law, but her team described the cost surge as a “big concern.”

The renewed emphasis on health care gave battered Republican House and Senate candidates a brief respite from months of painful questions about their presidential nominee, who has questioned the integrity of the U.S. election system while facing personal allegations of sexual misconduct. Trump has denied any wrongdoing.

“My first day in office I'm going to ask Congress to put a bill on my desk getting rid of this disastrous law,” a fiery Trump told thousands of voters gathered at a central Florida airport.

Trump vowed to replace the program — a key part of Obama's domestic legacy — “with something much less expensive, otherwise this country is in much worse shape than anybody thought.”

But he provided no specifics on how he would do that.

During a radio interview Tuesday, Clinton touted the Affordable Care Act as “a major step” forward and vowed, as she has before, to “fix problems” with the law.

“I'm sure you noticed, predominantly working people, African-American, Latino people now have access to insurance, but the costs have gone up too much,” Clinton told WHQT-FM in Miami. “So we're going to really tackle that. We're going to get co-pays and premiums and deductibles down. We're going to tackle prescription drug costs. And we can do that without ripping away the insurance that people now have.”

Blessed with an unexpected political gift, however, it's unclear whether Trump will be able to capitalize.

Trump has struggled to stay focused on the traditional issues throughout his outsider candidacy. He opened Tuesday by promoting one of his Florida golf resorts, highlighting the extraordinary intersection between his business and political interests. Trump is also scheduled to attend Wednesday's opening of his new Washington hotel.

“We're at Trump National Doral. And it's one of the great places on Earth,” Trump said during a visit to his golf club. He encouraged his employees to praise him at the microphone and said many of them are having “tremendous problems with Obamacare.”

The Doral general manager later clarified that 95 percent of the club's employees are on company-provided insurance.

Also Tuesday, Clinton picked up the endorsement of former Secretary of State Colin Powell, a Republican who announced his intention to vote for her during an appearance in New York.

Meanwhile, Libertarian vice presidential candidate William Weld is urging voters torn between major-party presidential candidates Clinton and Trump to reject Trump.

Weld offered a blistering critique of Trump, saying that while the Republican presidential nominee has demonstrated charisma and panache, he also has shown an inability to handle criticism, conjured up enemies and stirred up envy, resentment and group hatred, demonstrating “the worst of American politics.”

Trump, who must win the battleground state of Florida to have any chance at the 270 electoral votes needed to win the presidency, appeared at three campaign events Tuesday, his third straight day in the state. Clinton, who can win the presidency with or without Florida, made one appearance on the first day of a two-day swing.

Trump's finance chairman, Steven Mnuchin, said the GOP nominee has no further high-dollar fundraising events planned, dealing another blow to the GOP's effort to finance its get-out-the-vote operation.

The campaign's last formal fundraiser was Oct. 19 in Las Vegas, on the day of the final presidential debate. “We've kind of wound down,” Mnuchin said, referring to formal fundraisers. “But the online fundraising continues to be strong.”

While Clinton headlined her last fundraiser Tuesday night in Miami, her campaign has scheduled 41 other events between now and Nov. 3 featuring high-profile surrogates such as her daughter, Chelsea, running mate Tim Kaine and the entertainer Cher, according to a schedule sent to donors this weekend.

Mnuchin said the Trump campaign decided to keep the candidate's final weeks focused on taking his message to the voters rather than on raising money.

Trump also announced that running mate Mike Pence will visit Wednesday in Utah, where polls show Trump is at risk of losing a once-reliable GOP state.

The Washington Post contributed.