MADISON, Wis. (AP) _ Scott McCallum was sworn in Thursday as Wisconsin's 43rd governor to replace Tommy Thompson, who is joining President Bush's Cabinet.

A subdued Thompson, Bush's health and human services secretary, resigned and bid the state goodbye before introducing fellow Republican McCallum, who served as lieutenant governor for all of Thompson's 14 years in office.

``Now we must assume new roles. I can say without reservation that Scott McCallum is going to be a great governor,'' Thompson said.

Chief Justice Shirley Abrahamson administered the oath to McCallum in front of a packed Capitol rotunda, where he was surrounded by his family.

McCallum pledged his new administration will be ``part old, part new, but all Wisconsin.''

He said his top priority would be tax cuts, and promised to end the perception of Wisconsin as a high-tax state.

``Easing the tax burden on state taxpayers will require a new spending discipline on the part of Wisconsin's government, but it is time,'' McCallum said.