Hillary Clinton's message to US voters: Don't be misled by Donald Trump

Hillary Clinton and running mate Tim Kaine arrive in Columbus, Ohio on their bus trip. Photo / AP

As Hillary Clinton closed a three-day bus tour with a stop in Columbus, Ohio, she had a dire warning for US voters: Don't be "misled" by Donald Trump.

"I want people to have made an informed choice," Clinton said. "I don't want folks to be misled, to listen to the rhetoric and the demagoguery."

"I think Donald Trump poses a serious threat to our democracy, and it's going to be up to all of us to repudiate the hatefulness," she added.

The comments came at the tail end of her journey through two battleground states - Ohio and Pennsylvania - with stops focused on swing or Republican voters. Clinton travelled with her running mate Senator Tim Kaine and his wife Anne Holton. Former president Bill Clinton joined the group for several stops on the tour.

The bus tour comes as Trump is embroiled in controversy over his response to criticism from the family of a fallen soldier at the Democratic National Convention in Philadelphia last week.

Clinton defended Khizr Khan and his wife Ghazala, whose son - Army Captain Humayun Khan - was killed in Iraq in 2004.

Clinton denounced Trump's "attacks on distinguished military leaders" and accused him of "insulting the family of a fallen soldier - Captain Khan, an American Muslim who sacrificed his life to protect his unit and other soldiers as a taxi raced toward a base containing a bomb".

After the Khans appeared at the convention, Trump expressed some criticism in an interview with ABC, suggesting that Ghazala Khan was not permitted to speak because she is Muslim. Ghazala Khan has since said that she was unable to speak because she is still overcome with grief over the loss of her son.

Earlier, Clinton called Trump's comments on the Khans part of a pattern.

"One doesn't know where the bottom is," Clinton said in Ashland, Ohio. "It's hard to imagine anyone who has ever run to be president of the United States saying any of what he said."

"And the accumulation of it all is just beyond my comprehension," she added.

But Clinton declined to comment on what Trump's statements say about his character, remarking only that he is "temperamentally unfit and unqualified" to serve as president.

Speaking in Columbus, she returned to Khizr Khan's speech and noted his invocation of the principles of religious liberty "enshrined" in the founding of the country.

Captain Khan and his family represent the best of America, and we salute them. pic.twitter.com/MGeJXPF2DE

— Hillary Clinton (@HillaryClinton) July 30, 2016

"When his father spoke at the convention and pulled out a copy of the Constitution, it was so fitting that that happened in Philadelphia, where our country started 240 years ago," she added.

"George Washington, Thomas Jefferson - they addressed different religions, including Islam, that were present in America from the very beginning.

"I want all of us to stand for freedom and equality and justice and opportunity now and forever."