"We need a governor who realizes that our tax burden in Wisconsin is too large," Walker said at a news conference with his family in front of his Wauwatosa home. "Having the sixth highest tax burden in the country is simply unacceptable and I am prepared to sign the tax freeze into law."

"So the special interests who support this government do not intimidate me or our growing band of supporters," he said. "We've been up against worse, and we and the taxpayers came out winners."

Doyle spokeswoman Melanie Fonder said the governor was proud of his record that includes almost 70,000 new jobs in Wisconsin over the past year, fixing one of the biggest deficits in state history without raising taxes and protecting programs for the state's elderly and needy.

Walker said his time as county executive has lead to dramatic changes in Milwaukee County's government. He said he has presented three budgets that froze the county's property tax levy, reformed government operations and created a job-friendly business environment.

Though the race is still almost two years away, Walker has said an early start is important to compete with Doyle on fund-raising.