Sen. Barack Obama (Ill.) extended his primary victory streak to nine Tuesday night after being projected to be the winner in Wisconsin’s Democratic primary over Sen. Hillary Rodham Clinton (N.Y.).

The Badger State win is sure to raise new questions about Clinton’s strategy to rely on wins in Ohio and Texas, which do not hold their primaries until March 4. After giving up a significant head start in the state to Obama, the former first lady campaign heavily in the state.

The state represented some of the most negative campaigning in the contentious race to date. Clinton ran ads accusing Obama of ducking an invitation to debate.

Howard Wolfson, Clinton’s spokesman, repeated the charge on a conference call Tuesday.

“He does not like to debate in states where he’s ahead,” Wolfson said.

Wolfson added that the Clinton campaign “worked hard” in Wisconsin, but it did not spend as much time or money there as Obama did.

The state was thought to be a strong one for Obama because of its open primary and the Illinois senator’s proven strength with independent voters.

On the Republican side, presumptive nominee Sen. John McCain (Ariz.) won comfortably.