Clinton, Trump war of words escalates as race narrows.

Hillary Clinton and Donald Trump, sensing the urgency of a presidential campaign entering its home stretch, assailed one another on multiple fronts and in coarse terms Tuesday as new data showed the candidates in a dead heat.

It was another day of scathing rebukes, intense rhetoric and tit-for-tat accusations as the bitter rivals sought to claim the advantage with voters just nine weeks before the November 8 election.

In Florida, Clinton branded Trump a "demagogue" and declared his campaign to be "one long insult."

After the brash billionaire made a sudden trip to Mexico last week to meet President Enrique Pena Nieto, Clinton said Trump choked because he failed to discuss his demand that Mexico pay for Trump's border wall.

"Let me just tell you about choking," Trump fumed to ABC. "I don't choke. She chokes."

Trump has edged ahead of Clinton in a new CNN/ORC poll, at 45 percent to 43 percent among likely voters, while an NBC News poll of registered voters shows Clinton's lead holding at six percentage points -- 48 percent to 42 percent.

Another survey, by The Washington Post, looking at all 50 states shows Clinton with a solid lead in terms of electoral college votes, and even strength in some traditional Republican strongholds.

Clinton said she pays no attention to polls.

"We're sticking with our strategy, we feel very good about where we are," she said.

But the polls show how close the race is looking ahead of the vote, making the battle for the so-called swing states all the more critical.

Clinton rallied supporters at a voter registration event in swing state Florida, while the billionaire real estate mogul held a town hall meeting with military veterans before heading to North Carolina for an evening campaign rally.

"We have 62 days -- just 62 days -- to make the case, and I can't do it without you," Clinton said in Tampa.

The candidates have less than three weeks before the first of three scheduled presidential debates -- expected to be the most watched moments of an already raucous campaign.

- 'Coming after me' -

Clinton, in the national eye for three decades, shrugged off the intense nature of Republican attacks against her, including a call for a fresh congressional investigation of the Clinton Foundation following reports that donors gained inappropriate access to her while she was secretary of state.

"I believe I'm the best person for this job and I believe they're going to keep coming after me," Clinton told reporters.

With Monday's Labor Day holiday kicking off the final dash to Election Day, Clinton took pains to make herself more than available to reporters traveling with her, after nearly nine months without holding a formal press conference.

She took questions for more than 20 minutes on her plane for a second straight day.

Clinton said Trump was "dead wrong" for saying his tax returns were not the concern of everyday Americans, despite every major presidential nominee since Richard Nixon releasing their taxes before the election.

"I think it is a fundamental issue about him in this campaign that we're going to talk about in one way or another for the next 62 days. Because he clearly has something to hide," Clinton said.

- 'She's a disaster' -
While Clinton repeated her charge that Trump is "temperamentally unfit" for office, Trump assured veterans in Virginia Beach that he was in their corner, and used the opportunity to slam Clinton's ineffectiveness as a top diplomat and politician.

"She's a disaster in so many different ways, folks," he said.

"You have illegal immigrants that she wants... treated better than veterans."

Clinton is promoting a pathway to citizenship for many of the 11 million people living in the shadows, while Trump wants to curtail immigration and require that those who wish to gain legalized status must leave the country first.

The two also exchanged shots about national security, with Trump warning that Clinton would be unable to stand up to adversaries like President Vladimir Putin of Russia.

"Putin looks at her and he laughs," Trump said.

Trump released a letter in which 88 retired generals and admirals endorsed him, a revelation dismissed by Clinton.

"I think we're up to 89, but who's counting?" she quipped, noting how several Republican national security figures openly support her.

She also upbraided him for saying he would have stayed on his plane and left China if he were treated as President Barack Obama was last week when he was forced to exit Air Force One from a rear door.

Tampa Mayor Bob Buckhorn pointed to the hard-knuckled political battle ahead and urged Clinton to hit Trump relentlessly.

"Once you get someone down, you keep your foot on their throat," Buckhorn told AFP. "If I'm her, I'm hammering him every day and not letting up."