Your Grammar Nazi

This is actually a problem of innumeracy, but it's extremely common today, especially in political writing. And I'm sorry to say the latest example I saw comes from Kevin Drum, who absolutely knows better:

And especially young women voters: in the last two elections, they've voted for Obama by whopping margins of 69 and 66 percent.

No, young women voters certainly did not vote for Obama by margins of 69 percent and 66 percent. Young women voters gave him 69 percent and 66 percent of their vote. They voted for him by margins of 38 and 32 points.

How much of the vote a candidate receives is expressed in a percentage: 47 percent, 51 percent, 69 percent.

The difference between the percentage of vote one candidate receives and the other candidate receives is expressed in points: two points, 10 points, 30 points. This is the margin of victory.

A candidate who received 69 percent of the vote has a 38-point margin of victory over his opponent who receives 31 percent of the vote. 69 is 38 points more than 31.

A similar mistake is to say that a winning percentage of 69 is a 2-to-1 margin of victory. No, it isn't. A 69-percent win is a 2-to-1 victory, but still just a 38-point margin.

For Obama to have a 69-point margin (the phrase "69-percent margin" is gibberish), he would have had to receive 84.5 percent of the votes of young women. 84.5 percent is 69 points more than the 15.5 percent remaining for his opponent.

In 2008 and 2012, young women really fucking hated the repug candidates, but not by more than 60 points.