RENEE MONTAGNE, HOST:
And at his stops in Michigan yesterday, Rick Santorum spoke of economic revival through low taxes, fewer regulations and his commitment to conservative family values.
Here's NPR national political correspondent Don Gonyea.
DON GONYEA, BYLINE: Rick Santorum can't outspend Romney in Michigan, and he's facing a barrage of ads on radio and TV paid for by the pro-Romney superPAC Restore Our Future. The ads attack Santorum's U.S. Senate record.
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