Mitt Romney’s margins in Michigan and Ohio — the Associated Press has called Ohio for Mr. Romney, although The New York Times has not yet – weren’t much different from one another: 3.2 percentage points in the former state, and 1.0 percentage points in the latter.

But the benefit of winning a state is mostly symbolic, especially in a state like Ohio which divides most of its delegates by Congressional district and the remainder proportionately. And the aesthetics of Ohio and Michigan were much different, although for somewhat arbitrary reasons.

Michigan counted its vote very quickly, and Mr. Romney led almost the whole way along — often by slightly larger than the 3.2 point margin that he wound up with.

Ohio counted its vote slowly, and Mr. Romney trailed for most of the evening, sometimes by as many as 3 or 4 points.

In Michigan, Mr. Romney’s win came by a slightly larger margin than polls expected, but the difference was in well within most survey’s margin of error. In Ohio, Mr. Romney leads by a slightly smaller margin than some polls called for, but the polling average was nevertheless very close.

Mr. Romney’s narrow win in Michigan came at a time when his campaign seemed to be struggling. His probable win in Ohio came when he seemed to have the momentum and expectations were higher.

In Michigan, there was nothing else to look at except for that state’s results — that and Arizona, where Mr. Romney did very well. But on Tuesday night, Mr. Romney had lost four other states by the time that the A.P. called Ohio, changing the context that Ohio was viewed in.

Should any of this matter? In my view, it probably shouldn’t. In fact, I tend to find Mr. Romney’s one-point lead in Ohio more impressive than his three-point win in Michigan since the latter was his home state — something that is probably worth at least several points to him.

But, factors like these do affect the way that the results are reported upon and can therefore affect the momentum of the race, for better or for worse.

— NATE SILVER