(NOTE: The following is a guest post by Alan Abramowitz, who is Alben W. Barkley Professor of Political Science at Emory University, and a member of The Democratic Strategist’s Advisory Board).
Now that Arizona Senator John McCain has all but sewn up the Republican presidential nomination, the first task that faces him is winning over disgruntled conservatives, many of whom were supporting former Massachusetts Governor Mitt Romney in the Republican primaries. To that end, McCain gave a conciliatory speech on February 8th at the Conservative Political Action Conference in Washington, DC, pleading with conservative leaders and activists to unite behind his candidacy.
Meanwhile the two remaining Democratic candidates, Hillary Clinton and Barack Obama, are locked in a tight battle that could go on for several more weeks and possibly continue all the way to the Democratic convention. This has led to growing concern among Democratic leaders that a protracted battle between Clinton and Obama could make it difficult to unite the party for the general election campaign.
It is clear that unifying their respective parties will be a key task for both John McCain and the eventual Democratic nominee. But for which party’s nominee will this task be more difficult? The answer to this question will depend in part on how deep the ideological divisions are between supporters of the nominee and supporters of the defeated candidates in each party.
In order to compare the difficulty of the task that John McCain faces with the difficulty of the task that will face either Hillary Clinton or Barack Obama, I compared the ideological preferences of each candidate’s supporters based on data collected in the Democratic and Republican exit polls for California on Super Tuesday. I used exit poll data from California because California was by far the biggest prize in both parties, none of the candidates is from the state, and the primary was hotly contested in both parties.
I calculated the mean score of each candidate’s supporters on a five-point liberal-conservative scale that was included on the exit poll. The scores on this scale were 1 for very liberal, 2 for somewhat liberal, 3 for moderate, 4 for somewhat conservative, and 5 for very conservative. Thus a mean score of 3.0 would indicate that the average supporter of a candidate was right in the middle of the liberal-conservative scale while a mean score of 2.0 would indicate that the average supporter of a candidate was well to the left of center and a mean score of 4.0 would indicate that the average supporter of a candidate was well to the right of center.
The results of my calculations showed that the mean scores for Clinton and Obama supporters were almost identical: 2.5 for Clinton voters vs. 2.4 for Obama voters. In contrast, the mean scores for McCain and Romney supporters were quite distinct: 3.5 for McCain voters vs. 4.1 for Romney voters. The ideological divide between McCain and Romney voters was six times as large as the ideological divide between Clinton and Obama voters. And on this sort of scale with a very limited range, that is a very large difference.
The average Obama and Clinton voter was a moderate liberal. Similarly, the average McCain voter was a moderate conservative. McCain voters were about as far to the right of center as Clinton and Obama voters were to the left of center. But Romney voters were much further to the right of center. Given that Americans generally don’t like to place themselves at the extremes on these sorts of scales, it is striking that 40 percent of Romney voters in California placed themselves at the far right end of the scale. In contrast, only 12 percent of McCain voters placed themselves at the far right end of the scale and only 18 percent of Clinton voters and 22 percent of Obama voters placed themselves at the far left end of the scale.
These results suggest that despite clinching his party’s nomination much earlier than his Democratic opponent, John McCain may face a more difficult challenge in uniting his party’s voters than either Hillary Clinton or Barack Obama. Because supporters of Clinton and Obama have almost identical ideological preferences, it should not be difficult for either group to unite behind the other candidate if he or she wins the nomination. The winning candidate will not need to move to the left or right in order to win over supporters of the defeated candidate.
John McCain, however, may be forced to move further to the right in the next few weeks in order to win over disappointed supporters of Mitt Romney. In fact, this is precisely the course of action that is being urged on him by conservative spokesmen and it appears to be what he was attempting to do in his speech to the Conservative Political Action Conference, a group that he shunned only a year ago. But this may be a risky strategy for McCain since it will delay if not prevent him from moving back to the center to appeal to independents and swing voters in the general election-a move that will be crucial if he is to have any chance of winning in November.