By New York Times News Service
MITT ROMNEY HAS won the Republican presidential primary in Arizona, based on preliminary exit polling, but is locked in a tight battle with Rick Santorum in Michigan, a crucial electoral battleground where Romney’s hometown advantage has all but evaporated.
Romney’s victory in Arizona will earn him 29 delegates, extending the lead he already enjoys over his rivals.
The win comes after his rivals largely conceded that Romney, the former Massachusetts governor, would take the border state.
But Michigan has been a much tougher challenge for Romney, who was raised in the state and whose father served as the state’s governor.
Exit polls and early returns showed Santorum mounting a fierce challenge to Romney in a state that was not expected to be close just weeks ago.
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