"Everybody who pays taxes ought to get relief," the Republican presidential nominee said at his first stop â€“ a children's hospital â€“ where he was flanked by middle-class couples with children.
Saying that Mr. Gore's plan would provide no relief for 50 million Americans, Mr. Bush noted, "It's so targeted, it misses the target."
Democrats have said that Mr. Bush's $1.3 trillion tax cut plan is too expensive, would endanger Social Security and would benefit mostly the rich.
Gore aides said their $500 billion tax-cut plan would not only provide relief to middle and working class families but also help them finance health care, education and retirement savings.
They said Mr. Bush's across-the-board tax cut will benefit only the rich.
"We use the prosperity to benefit the many," Gore spokesman Chris Lehane said. "[Mr. Bush] spends the entire surplus on a massive tax cut for the wealthy few, leaving nothing for the many."
But the Texas governor said Mr. Gore's plan is full "of fine print. You get tax relief only if you behave a certain way."
"I don't think government ought to try to pick winners. I think the right people are all people in America," he said, noting that 60 percent of his own tax-cut plan "goes to middle-class families to help themselves."
"Everybody who pays taxes ought to get tax relief," he said.Among Mr. Bush's proposals are lowering the tax rate across the board, cutting the marriage tax penalty, eliminating the death tax and doubling the child tax credit from $500 to $1,000 per child.
"A family of four making $35,000 will get a 100 percent tax cut on their federal taxes under my plan and they will save $1,500 a year," Mr. Bush said on the first stop of a six-day swing during which he will stress issues important to middle-class voters.
"I strongly believe that the tax burden on the American families makes it harder for families to realize their responsibilities to do their duties," he said. "The average family now pays more in all taxes than they do in housing, food and clothing combined.
"High taxes rob families of time to be with each other and of time to be with their children," he said. Mr. Bush made the same pitch at a town hall meeting in Kansas City, Mo.
Meanwhile, Mr. Bush's aides took after Mr. Gore for saying recently that his mother-in-law pays nearly three times as much for the same arthritis medicine used for her ailing dog, Shiloh.
The Boston Globe reported Monday that Mr. Gore had mangled the facts and that aides to Mr. Gore now concede they can't say for sure that his mother-in-law and Shiloh actually take the same drug.
The Globe reported that Gore campaign officials said they took the cost figures for the medicine not from Mr. Gore's family bills, but from a House Democratic study. The article also said generic equivalents of the drug for humans, Lodine, can be purchased for about the same as for the dog.
"Someone who makes up numbers about their mother-in-law, about their dog and their prescription medicine, that's alarming," said Bush spokesman Karen Hughes. She said Mr. Gore "apparently is willing to make up stories" to try and appeal to Americans' emotions.
Gore spokeswoman Kym Spell said that bringing the issue up was another example of "the Bush campaign's spinning around."
"The Bush campaign ought to stop whimpering and whining and come up with a good prescription plan," Mr. Lehane said.
Staff writer David Jackson in Las Vegas and the Associated Press contributed to this report.