March 15 Exit Poll Results: The Polarization of Primary Electorates

Political polarization has been a frequent topic of conversation among political observers over the past decade as Democratic and Republican legislators and voters appear to have moved further apart ideologically. The same pattern is visible in the electorates voting Tuesday. Voters in Democratic primaries are considerably more liberal than they were eight years ago, and Republican voters are more conservative than in 2008.

According to the NBC News Exit Polls in the five Democratic contests Tuesday, there has been a 15-point increase since 2008 in the percentage of voters who describe their political ideology as “liberal.” On Tuesday, about one-third of Democrats described themselves as moderate—an 9-point drop since 2008—and now fewer than one in 10 characterize their political thinking as conservative.

Among Republicans in four of the five states Tuesday (North Carolina was excluded because it did not have the comparable trend data) there has been growth since 2008 in the percentage describing their political ideology as “conservative.” In 2008, 63 percent of Republicans across the four states self-identified as conservatives. On Tuesday, 73 percent did so, an overall increase of 10 points. Slightly fewer now consider themselves moderates—down 4 points to 24 percent. And eight years ago, 9 percent of Republican primary voters in these states said they were liberal, a figure that has dwindled to 3 percent today.