Donald Trump is surging in new battleground and national polls at a time when Hillary Clinton faces tough questions not only about her health but her sweeping criticism of her Republican opponent’s supporters.

Several surveys appear to show the Republican presidential nominee effectively ending, at least for now, a post-convention slump that saw Clinton leading in virtually every swing state. Now, a Monmouth University Poll shows Trump taking a narrow 2-point lead in Nevada; a Bloomberg Politics poll shows Trump leading Clinton by 5 points in Ohio; and new CNN/ORC polls show Trump leading in Florida and Ohio.

In the latter survey, Trump leads 46-41 percent among likely voters in Ohio, and 47-44 percent among likely voters in Florida.

Meanwhile, a Los Angeles Times tracking poll shows Trump taking a 6-point national lead.

“We’ve really had a good month,” Trump told Fox News’ “Fox & Friends,” claiming he’s enjoying renewed “enthusiasm” from voters.

Clinton, though, plans to return to the campaign trail Thursday afternoon after taking three days off to recover from a bout of pneumonia. While her campaign dispatched high-powered surrogates to the stump in her absence -- including Bill Clinton and President Obama -- the Democratic nominee’s presence could help reset the race once again.

The contest remains tight, and the polls are hardly uniform. A Quinnipiac University national poll released Wednesday showed Clinton leading 48-43 percent among likely voters.

But that still represents a narrowing of the race since a late-August survey showing Clinton up 10 points.

The recent surveys come as Clinton grapples with new controversies on two fronts: Her comment at a Friday fundraiser that half of Trump’s backers are in a “basket of deplorables,” and her campaign’s handling of a health scare on Sunday during a 15th anniversary ceremony honoring victims of the Sept. 11 terrorist attacks.

Clinton has since expressed regret for her “deplorables” comment, though Trump has called on her to outright retract it. And Clinton’s campaign has sought to answer questions about the former secretary of state's health, after Clinton was seen stumbling at the 9/11 memorial event in New York City.

The campaign said she was overheated and dehydrated, and revealed she had been diagnosed with pneumonia on Friday. While the incident revived long-simmering questions about her health, the campaign on Wednesday released additional medical details. Dr. Lisa Bardack, Clinton’s physician, said she is “recovering well with antibiotics and rest.”

Bardack also said Clinton remains “healthy and fit to serve.”

Trump, too, has tried to answer questions about his own health. He discussed the results of a recent physical with TV’s “Dr. Oz,” and told Fox News on Thursday “they were good.” The discussion with “Dr. Oz” will air on his show Thursday.

Meanwhile, the Clinton campaign maintains they always knew states like Ohio would be competitive – and they are building out their operation there.

The campaign announced that they will open a half-dozen new offices in the state, bringing their total to 54.