The Bush camp fired back, saying that the Texas governor has the support of leaders in high technology.
"America cannot afford to have a president in the 21st century who doesn't understand the terrain of the new economy," Mr. Lieberman told more than 2,000 members of the Communication Workers of America at their convention.
The vice-presidential candidate did not mention Mr. Bush by name, but his speech fell into a Democratic strategy of painting Mr. Bush as an intellectual lightweight.
"It's just this simple: We as a nation cannot afford to make Barney Rubble investments in a George Jetson world," said Mr. Lieberman, referring to old cartoon series about Stone Age and space-age families.
Mr. Bush, responding from New Hampshire, told reporters, "Americans are tired of name-calling."
And Bush campaign spokesman Dan Bartlett said the Texas governor has been endorsed by many leaders of the high-tech world, including Dell Computer Corp. Chairman Michael Dell.
"Texas leads the nation in high-tech job growth," Mr. Bartlett said. "He not only understands the economy, but they [high-tech leaders] believe he's the one who can foster it and make it grow even more."
Vice President Al Gore has been at the forefront in ensuring that the rights of working men and women have been protected as companies have integrated computers and other new technology, Mr. Lieberman said.
A Gore-Lieberman administration would spend $2 billion to retrain workers who are laid off because of technology improvements and help pay for adult learning, Mr. Lieberman said.