This analysis was written by CBS News political consultant Monika McDermott.
Now that the two major parties have their 2008 presidential nominees, looking back at the primary election exit polls can tell us something about what lies ahead in the general election match-up between and . The candidates have much in common - both have potential problems with their party base vote, and both have demonstrated appeal to independent voters. There are key differences, however, that affect their chances of winning.
The Obama Vote
Obama has demonstrated both strengths and weaknesses this primary season. One big strength has been among first time voters. He has also performed well with independents - a potentially crucial factor in the general election. At the same time, his consistent inability to win the votes of white downscale voters has become an election issue wielded by Hillary Clinton as a damning weakness for the general election.
Electoral turnout in the Democratic primaries this year has been off the charts. According to the exit polls, voters who have never voted in a primary election before have made up 22 percent of the Democratic primary electorates across the country. These numbers dwarf those in the 2004 Democratic primaries. For example, in the 2004 primary in Virginia, 25 percent of voters reported never having voted in a primary (or at all) before. This year 37 percent of Virginia's Democratic primary electorate were new primary voters - a 12 point increase.
This flood of new voters has benefited Obama. Across the exit poll states in which the first-time voter question was asked, Obama received 65 percent of the vote from those who had either never voted in a presidential primary before, or never voted at all. Even in states Clinton won, Obama easily carried these new voters - for example by 20 points in Indiana.
A disproportionate share of these first-time voters have been younger voters, a group with which Obama has also had tremendous success. In Maryland, for example, voters ages 18 through 29 made up 43 percent of new voters. In Indiana young voters were 44 percent of the new voter group.
These voters are clearly turning out to support Obama, the question is whether this group, notorious for not voting, will show up in the general election. Census figures show that in presidential elections since 1980, turnout of eligible 18 to 29 year-olds has lagged behind turnout among those 30 years old or older by at least 20 points. While their support could prove decisive for Obama if they show up, counting on them could be a risky move.
While Obama's attraction of new voters is a definite plus, he has also shown one notable weakness - his inability to win the support of less educated white voters. For example, even in the state of Oregon which Obama recently won by 16 points, Clinton turned the tables on him among white voters with high school educations or less. These voters supported Clinton over Obama by 17 points - 58 percent to 41 percent.
There is reason to believe these white Democratic voters with lower education levels might not 'come home' to Obama in the general election. First, these voters have been consistently and overwhelmingly supportive of Clinton over Obama - in all primary states combined, whites with less education have supported Clinton 68 percent to only 26 percent for Obama. Additionally, these voters have made clear their discontent with an Obama nomination. Fifty-two percent said they would be dissatisfied if Obama were the Democratic nominee, while only 48 percent would be satisfied.
As a base group in the general election, white Democrats with a high school education or less are not sizable, but they are not negligible either. These voters comprised only 6 percent of the overall electorate in 2004, but they made up 11 percent of Kerry's vote total. Potentially losing this tenth of support should be a concern to the Obama campaign, especially when it comes to important battleground states in which these voters are more plentiful. In 2004, white Democrats with a high school education or less constituted 10 percent of the Missouri general electorate, and nine percent of Ohio's.
The McCain Vote
McCain's problem within the Republican fold is less entrenched, although potentially much larger in magnitude. Many pundits and party members assumed McCain would have trouble wooing the important voting bloc of white evangelical Christians. This was only partially true in the primaries, however. While McCain did not do nearly as well among these voters as among non-evangelicals in the Republican primaries, he does not appear to have alienated them either.
Across all of the Republican exit poll states to date, the white evangelical vote has gone to Mike Huckabee. He garnered 39 percent of this vote, compared to 33 percent for McCain and 20 percent for Romney. While only trailing Huckabee by six points among white evangelicals, McCain's performance is decidedly lower than the 42 percent of primary votes he has received overall.
McCain's relatively low support among white evangelicals does not necessarily mean he has lost them for the general election, however. Unlike the divided electorate in the Democratic primaries, white evangelicals in the Republican primaries were accepting of a McCain nomination. In the three states in which the question was asked of Republicans (OH, TX and VT), white evangelicals showed similar levels of satisfaction with the prospect of a McCain nomination as non-evangelicals did - 71 percent to 76 percent.
Should McCain's relationship with evangelicals turn sour, however, his situation would be far more dire than Obama's. White evangelical Republicans were 14 percent of the 2004 general electorate. More importantly, white evangelical Republicans comprised 25 percent of Bush's vote, favoring him 97 percent to three percent for Kerry. Losing this bloc of support, or even a portion of it, would be fatal to McCain's candidacy.
Independent Voters in the General Election
Conventional wisdom holds that self-identified independent voters are the ones who can make the difference in a general election. With close to 90 percent of each party's identifiers supporting their party's nominee in presidential elections, independents become the understandable focus. They are a substantial proportion of the general electorate, and a closely divided group nationally. They made up 22 percent of the electorate in both 2000 and 2004, and they split nearly evenly in their vote preference - 50 percent chose Kerry and 47 percent chose Bush in '04, and they voted 48 percent for Bush and 45 percent for Gore in '00.
Both Obama and McCain have demonstrated popularity among independent voters this primary season. Among all primary states, Obama has won 54 percent of the Democratic primary vote from independents compared to his 48 percent support overall. Across the Republican primary states McCain edged out his opponents on the independent vote, having received 46 percent of the independent vote in the Republican primaries, compared to his 42 percent support overall.
Similarly, there is only a marginal difference in the enthusiasm each party's independent primary participants express towards Obama's and McCain's candidacies. In states in which the exit polls asked about satisfaction with the potential nomination, 71 percent of Democratic primary independents said they would be satisfied with an Obama nomination. Sixty-six percent of Republican primary independents said they would be satisfied if McCain were the Republican nominee, five points lower than Obama's independents.
At this point in the election the only hard evidence we have of actual candidate performance comes from those voters participating in the party primaries. What matters now is which candidate will have the edge among general electorate independents.
Looking at independent voters in the 2004 general election, assuming the 2008 pool could be similar, these voters had at least two distinguishing characteristics: they were better educated than their partisan counterparts, 47 percent were college graduates compared to 41 percent of Democrats and 42 percent of Republicans; and they were substantially more likely to call themselves ideological moderates, 57 percent did, compared to 50 percent of Democrats and 34 percent of Republicans.
More importantly, these differences held within important swing states across the country. 2004 self-described independent voters in Florida, Ohio, Arizona and Washington all fit this same profile of better-educated moderates. And in all of these cases, even in the states that went Republican, Kerry won this independent vote.
Obama begins the election season with a head-start among independent voters for this reason. Even in a Republican year, swing state independents demonstrated a Democratic tendency, a built-in advantage for Obama. In addition, the well-educated have proven to be a solid base of support for Obama. For example, among the Super Tuesday primary states Obama performed five points better among those with a college education than he did overall.
Obama has not, however, demonstrated strength among ideologically moderate voters, while McCain has. Obama has consistently performed best among the liberal wing of the Democratic primary electorate - a group ideologically far removed from general election moderates. McCain, on the other hand, has the opposite appeal. His problems have been with the conservative base of his party, not the liberals and moderates. On Super Tuesday, McCain received 15 points more of the vote among moderates than he did overall.
While this would seem to give McCain the advantage ideologically these voters will not be easy to woo. In Florida in 2004, independents who called themselves moderate voted 66 percent to 33 percent for Kerry, and in Ohio they went 60 percent to 39 percent for him, demonstrating even stronger Democratic predispositions than independents overall.
Based both on their levels of independent voter support in the primaries, and the characteristics of typical independent voters, it appears that both Obama and McCain have some appeal, with Obama having an initial edge. As Kerry demonstrated in 2004, however, merely winning the independent vote is not enough to win a state. Obama has to best Kerry's independent performance substantially to take tough states like Ohio and Florida.
For this reason, party base votes will also be vital. Here Obama has real cause for concern with less educated white voters, especially in some battleground states, unless he can maintain the enthusiasm of his new voters to balance out the potential base loss. In contrast, to hold his base McCain may merely have to avoid angering the Republican evangelical voting bloc that appears satisfied with him to this point.
By Monika McDermott