Many pollsters and pundits pointed to Republican underperformance among independent and moderate swing voters as the cause of their mid-term congressional demise in 2006. Winning those voters back must be on the minds of many in the McCain high command and among GOP congressional election strategists. And while surveys still show the GOP lagging in party identification, the makeup of the electorate in the primaries to date tells a slightly different story.

This post by University of Wisconsin-Milwaukee political scientist Tom Holbrook breaks down the Republican and Democratic primaries (through Mississippi) and demonstrates the two parties are near mirror images of each other so far this year in attracting independent voters to their primaries. This is surprising given all the attention in the media surrounding the appeal of Barack Obama to these non-aligned voters.

According to Holbrook, "About 76% of the votes in each of the parties' primaries have come from their own partisans, 20% from independents and around 4% from the other party. The bottom line is that neither party is doing a better job attracting independents or rival partisans. Once again, this finding is a bit at odds with the common perception that the Democrats have been more successful at drawing independent voters."

Next Holbrook looks at the primary electorate from the standpoint of ideology, showing a different picture. Democratic primary voters break down 47.4% liberal, 39.8% moderate and 12.8% conservative. GOP primary voters are 54.8% conservative, 26.5% moderate and 8.7% liberal. He suggests the Democratic primaries so far this year may be more "ideologically heterogeneous." Probably true at one level. But "liberal" may still be somewhat of a pejorative among certain Democrats. So many of the "moderates" here may indeed be "liberals" in disguise. They just don’t choose that label with pollsters.