Romney wins Wisconsin GOP primary

Reporting from Washington — 

Mitt Romney has won the Republican presidential primary in Wisconsin, according to the Associated Press, delivering what could be a final blow to the sputtering candidacy of Rick Santorum.

As voters in Wisconsin, Maryland and the District of Columbia headed to the polls Tuesday, Wisconsin was the only state where Santorum stood a chance to win and the only state where he had campaigned.

The results in Wisconsin are not surprising -- Santorum had been trailing Romney in recent polls. But because the primary was open, there was the possibility that Democrats would turn out for Santorum in an effort to prolong the bruising GOP nominating campaign.

Santorum won 53% of Democrats, according to preliminary exit polls, but Democrats accounted for just 9% of the vote. Romney won with both Republicans and independents.

The Republican primary in the Badger State was overshadowed by the upcoming recall election of Gov. Scott Walker, who angered voters last year with his campaign to limit the power of public employee unions. Romney and Santorum both praised Walker as they campaigned in the state, but Walker kept his distance from the candidates.

Of Wisconsin’s 42 delegates to the GOP convention, 15 will be awarded to the statewide winner, 24 will be divided between the candidates based on results in each congressional district, and three are state party officials.

Going into Tuesday’s primaries, Romney had 572 delegates, Santorum 272, Newt Gingrich 135 and Ron Paul 51, according to the Associated Press.

The Associated Press and network news organizations projected Romney the winner in Wisconsin as well as Maryland based on exit polls.

Romney also won in the District of Columbia, according to the Associated Press. Santorum did not appear on the ballot there. Nineteen delegates are at stake in the District of Columbia primary, 16 of which will go to the winner while three will be unbound state party officials.

John McCain won the Wisconsin Republican primary in 2008 with 55% of the vote. Barack Obama carried the state in the general election.

kim.geiger@latimes.com