She accused him of supporting the "most extreme" version of trickle-down economics with his tax plan, saying he "trumped up trickle-down." Trump has called for across-the-board tax cuts, including income tax reductions for the wealthiest Americans and dropping the estate tax.
"Trickle down did not work," Clinton said, contending the country should "never go back to what got us in trouble in the first place."
Trump has proposed breaking income taxes down into three brackets for married or joint filers: 12 percent for taxable income of $75,000 or less, 25 percent on income between $75,000 and $225,000 and 33 percent on income above $225,000. The brackets for single filers will be set at half those levels.
Most of Clinton's tax policy has focused on drawing more from the wealthy. She has called for a 4 percent surcharge on taxpayers making more than $5 million per year and a minimum 30 percent effective rate for millionaires. She would also aim to close loopholes overseas and abroad that allow the rich to avoid some taxes.
Most independent analyses have estimated Trump's economic plan would grow the U.S. deficit more than Clinton's.
Trump claimed he was "very proud" of his tax cut, calling it the biggest since Reagan. He contended it would create new jobs by keeping businesses in the United States and boosting investment at home.
This is a developing story. Please check back for updates.