The Pennsylvania primary is in four and a half weeks, and the conventional wisdom is that the former First Lady has an edge in the Keystone State.

Does this intuition bear out on closer inspection? Real Clear Politics’ Horse Race Blog takes a look inside voting data posted by neighboring states to see if it’s reasonable to favor Hillary Clinton in Pennsylvania - and by how much.

Of all the demographic variables that seem to be driving election results, the two that may be the most powerful are 1. The number of African-Americans in a particular state and 2. How “upscale” the state’s white voters are.

A state’s African-American population has a curvilinear relationship with election results. In states with few African-Americans, Barack Obama does very well.

In states with many African-Americans, he also does well.

Clinton does well in states with a middling amount - say 5-15 percent.

The working hypothesis here is that Barack Obama is perceived differently by white voters depending upon the racial demography of the state.

The “upscale” variable, as observed thus far, captures the differences in the socioeconomic status of the whites in each candidate’s coalition.

In a sense, Hillary Clinton is winning “Mondale voters,” and Obama is winning “Hart voters,” according to this theory, measured via median white income.

These variables are not comprehensive explanatory factors.

Other causes are definitely influencing vote returns. However, these two can account for upwards of 60 percent of the vote results we have seen.

Thus, they give us a good starting point to analyze Pennsylvania.

The best approach is to contextualize Pennsylvania within the larger mid-Atlantic region. Comparing Pennsylvania’s to its five neighbors that have already voted in the Democratic race (Ohio, New York, New Jersey, Delaware and Maryland) can provide us with a sense of which neighbor might best serve as a guide.

Continue reading in the RCP Horse Race Blog …