There are 88 counties in Ohio. In 85 counties, there were more votes for Kerry than there were against State Issue 1. A vote against State Issue 1 was a vote against a constitutional amendment prohibiting gay marriage.
In 3 counties (Clermont, Delaware, and Warren), there were fewer votes for Kerry than against State Issue 1. The reported results suggest that some Bush voters crossed the line to vote against a constitutional amendment against gay marriage in these counties. (Bush voters for gay marriage?)
Bush won Ohio by 2.5%. State Issue 1 passed by a 23.5% margin. It is a significant deviation from the statewide average for the Issue 1 margin to be smaller than the Bush/Kerry margin.
Another interesting point is that Warren County was the site of the now-famous "secret" vote count, at which officials barred observers and members of the media due to homeland security concerns.
Reported results:
http://www.sos.state.oh.us/sos/results/index.html
A good article:
http://www.freepress.org/columns/display/3/2004/983
County results:
Clermont County:
Bush 61,694 For Issue 1: 57,013
Kerry 25,318 Against Issue 1: 26,492
Badnarik 148
Peroutka 90
Delaware County:
Bush 52,237 For Issue 1: 47,991
Kerry 26,491 Against Issue 1: 29,138
Badnarik 164
Peroutka 90
Warren County:
Bush 66,523 For Issue 1: 62,050
Kerry 25,399 Against Issue 1: 27,288
Badnarik 190
Peroutka 139
Note that there is a general tendency for the highest vote count to be at the top of the ticket. Some voters vote for President, and then ignore the lower-ticket races. It would be unusual for a liberal voter to enter the booth, vote against prohibiting gay marriage, and not cast a ballot for president.
These counties are demographically similar, as exurban counties near major cities (Clermont and Warren near Cincinnati, and Delaware near Columbus.) So maybe there is a reasonable explanation for this voting pattern. (suburban voters for Bush and gay marriage?)
I am not directly suggesting that any vote fraud happened. There is not any direct evidence. But, this is an unusual pattern which warrants thought.
And there is no disputing the importance of these counties. George Bush carried these three counties by a collective margin of 103,000 votes. George Bush won the presidency through these three counties with unusual voting patterns.