Speaking in Tampa, Florida, Clinton said the Republican nominee "does not speak for anyone" and was not the "voice" that he fashioned himself at the convention in Cleveland. And she took particular offense at Trump's claim that he "alone" could fix the country's problems, characterizing it as self-centered.
"His vision of America is one where we Americans are kind of helpless. We need to be rescued," she said. "I can't really imagine him on a white horse, but that seems to be what he is telling us: 'I alone can fix it.'"
Clinton also poked at the Republican Party's lack of unity, highlighted by a speech in which Texas Sen. Ted Cruz declined to endorse Trump.
"Something has gone terribly wrong when one speaker says vote your conscience and gets booed," Clinton said. "I never thought I would say these words, but Ted Cruz was right."
Referring to Trump's message as a "dark and divisive vision," Clinton said her Republican opponent "offered a lot of fear and anger and resentment but no solutions about anything that he even talked about."
And in response to Trump's line that "I am your voice," Clinton said that she doesn't believe the real estate mogul speaks for working Americans such as small business owners and housekeepers.
"I don't think he speaks for most Americans, do you?" Clinton asked.
She added, "I don't think he speaks for working families who would be devastated by his reckless economic policies. He doesn't speak for anyone who thinks our country should be standing together, not splintering apart. He sure doesn't speak for me because I know we are stronger together."
Trump's convention at times seemed to focus as much on the case against Clinton as it did the case in favor of Trump. Her record as secretary of state was described as calamitous, and delegates regularly broke into extended chants of "lock her up" in reference to her use of a private email server at the State Department.
During his acceptance speech
, Trump argued that many of the world's travails could be blamed on Clinton.
"Her bad instincts and her bad judgment -- something pointed out by Bernie Sanders -- are what caused so many of the disasters unfolding today," he said. "This is the legacy of Hillary Clinton: death, destruction terrorism and weakness, but Hillary Clinton's legacy doesn't have to be America's legacy."
Clinton had been expected to announce her running mate on Friday. As Clinton stepped off stage in Tampa, her vice presidential nominee remained unannounced, despite many in the audience hoping to know who Clinton's running mate would be by the time they left.
Soon after the event, however, she announced
Virginia Sen. Tim Kaine as her No. 2.