President Diversity, without any quotes or even a citation of the source anywhere in the paper: "the average turnout seems to increase linearly as African Americans become a larger proportion of the population. This is one sign that the data contain little aggregation bias. If racial turnout rates changed depending upon a precinct's racial mix, which is one way to think about bias, a linear form would be unlikely in a simple scatter plot. A linear form would only result if the changes in one race's turnout were compensated by changes in the turnout of the other race across the graph."
Source material: "The average turnout seems to decrease linearly as African Americans become a larger proportion of the population. This is one sign that the data contain little aggregation bias. If racial turnout rates changed depending upon a precinct's racial mix, which is one description of bias, a linear form would be unlikely in a simple scatter plot (resulting only when changes in one race's turnout rate somehow compensated for changes in the other's across the graph.)"
While this is a particularly egregious example due to the lack of quotes or even a citation (!), Harvard's honor code is unambiguous-- "It’s not enough to change a few words here and there and leave the rest... If your own language is too close to the original, then you are plagiarizing, even if you do provide a citation."