Today on Larry Sabato’s Crystal Ball, we take a look at another key aspect of Trende’s argument: the claim that white voters are trending strongly toward the GOP and that therefore Republicans can afford to ignore minority voters and double down on mobilizing whites. Please check out the whole article (and the tables and charts!) but here is a taste of our findings:
1. Trende’s claim that Republicans have increased their performance among white voters is based on his calculation of a statistic known as the PVI, or Partisan Voting Index, for white voters. The PVI for white voters compares the Democratic share of the vote among white voters with the Democratic share of the vote in the overall electorate. Over time, the PVI for white voters has become increasingly negative with an especially dramatic decline since 1992. But the interpretation of this result is not as straightforward as Trende suggests. That is because the PVI for white voters reflects both the Democratic margin among white voters and the size of the nonwhite electorate.
2. In fact, the main reason that the gap between the Democratic margin in the overall electorate and the Democratic margin among white voters has increased over time is not because whites have become more Republican but because nonwhites, who are overwhelmingly Democratic, now make up a larger share of the overall electorate. As just one example, the PVI of the white vote in 2012 (-24) was far more negative than it was in 1988 (-13). Yet Democratic margins among both whites were essentially the same in each election. The real change: nonwhites were just 15 percent of voters in 1988 compared to 28 percent in 2012.
3. When we directly examine the data on the Democratic margin among white voters over time, there is little evidence of any Republican trend. For all 16 presidential elections between 1952 and 2012, the correlation between years elapsed and Democratic margin among white voters is a slightly negative but statistically insignificant -.16. For the 10 presidential elections between 1976 and 2012, the correlation is a slightly positive and statistically insignificant .02. Based on these results, it is clear that the trend in the PVI for white voters over this time period is due almost entirely to the growing impact of nonwhite voters on electoral outcomes.
Our conclusion: the growing size of the nonwhite electorate constitutes a major challenge to the Republican Party in presidential elections. Unless Republicans improve their performance among Hispanics, African-Americans and other nonwhite voters, the task of capturing the White House is almost certainly going to become more and more difficult for them as the nonwhite share of the electorate continues to grow. Doubling down on white voters does not look like a very promising approach to restoring the White House to GOP control.