WASHINGTON--Mitt Romney stumps Tuesday at a machinery company in Salem, Va.--the southern part of an important battleground state--as the Obama team runs a new ad there hitting him on his Bain business credentials.

Other Obama ads--customized for battlegrounds Iowa and Ohio--are running in those states. Vice President Joe Biden--who hit Chicago on Monday for a fund-raising at a Lincoln Park home--is campaigning in Waterloo, Ia.