Presidential candidate Mitt Romney is letting TV ads do the dirty work in Michigan while he stays on the high road with voters.
Romney told several hundred people at a rally Wednesday in Grand Rapids that he would do much better at leading the economy than President Barack Obama.
But the former Massachusetts governor made no reference to his Republican rivals. Polls show former Sen. Rick Santorum making a surge nationally.
Santorum is making a play for Michigan's Feb. 28 primary. A Santorum victory there could be embarrassing for Romney, who grew up in Michigan. His father, George, was a top auto executive and three-term governor.
A pro-Romney PAC is airing TV ads calling Santorum a big spender and Washington insider. Romney is heavily outspending Santorum on the air.