Cuyahoga (Cleveland): 2004: Kerry 448,503 vs. Bush 221,600 (+226,903); 2008: Obama 458,422 vs. McCain 199,880 (+258,542)
Franklin (Columbus): 2004: Kerry 285,801 vs. Bush 237,253 (+48,548); 2008: Obama 334,709 vs. McCain 218,486 (+116,223)
Hamilton (Cincinnati): 2004: Bush 222,616 vs. Kerry 199,679 (+22,937); 2008: Obama 225,213 vs. McCain 195,530 (+29,683)
Lucas (Toledo): 2004 Kerry 132,715 vs. Bush 87,160 (+45,555); 2008: Obama 142,852 vs. McCain 73,706 (+69,146)

Both Bush and Obama received 51% of the vote in Ohio in 2004 and 2008. The one TRUE swing county is Hamilton, which both men won. But just as important are the margins. Note that Obama won the Democratic-leaning Cuyahoga and Lucas counties by wider margins than Kerry did, while Bush was able to minimize his losses in these two counties. So for the president, it’s about winning his counties by 2008 margins; for Romney, it’s about losing them by 2004 margins. What made Obama’s victory margins so impressive in 2008: There were fewer voters in Cuyahoga and Lucas. It’s a big reminder that for the Democrats, Ohio defies gravity for them.