Jonathan Martin of the New York Times reports on how Democratic Party strategists are hoping to maximize black turnout in order to preserve their Senate majority. One might question whether this really counts as news, given that black Americans have been voting overwhelmingly Democratic for a half-century: It always makes sense for Democrats to mobilize black turnout. But the fact that Democratic spinmeisters are evidently pitching this line carries a whiff of desperation. For the fact is that there are relatively few blacks in most of the states with seriously contested Senate races.

In the 2010 Census, 13.6 percent of Americans classified themselves as “black or African-American alone or in combination.” (Barack Obama, who made much of his biracial parentage, classified himself as black alone.) The black percentages, rounded off, in 13 states with seriously contested Senate races are shown in the table, together with the percentage of whites’ votes cast for Obama according to the exit poll in 2012 (in the states with exit polls that year) and 2008 (when exit polls were conducted in every state). The eight states with below-national-average black percentages are grouped together, as are the five states with above-national-average black percentages.