PORTSMOUTH, Ohio — The Republican ticket has all but taken up residence in vital Ohio: Mitt Romney spent four days in the state this week and Representative Paul D. Ryan two, with plans to return Monday.

Ohio, which two weeks ago seemed to be slipping from Mr. Romney’s grasp, has become a tighter contest, according to polls released late last week. The Republicans’ barnstorming was in response to state leaders who pressed Mr. Romney to help turn out voters.

As Mr. Romney and Mr. Ryan charted separate paths on Saturday, they tailored messages to each region — Mr. Ryan promising a return of manufacturing in the industrial northeast, Mr. Romney defending coal jobs on the banks of the Ohio River in the south.

Mr. Romney, who has never drawn the throngs typical of President Obama’s — 15,000 turned out to hear the president at Ohio State University early last week — has seen his crowds swell to some of the largest of his campaign, and he aimed an offhand barb at Mr. Obama on Saturday. “His campaign is about smaller and smaller things and our campaign is about bigger and bigger crowds,” Mr. Romney said at an outdoor rally on the campus of Shawnee State University.