Looking at the 'swing voters'

According to Inside Politics, Gallup did a meta survey that showed approx 45% of citizens consider themselves Republicans and 45% consider themselves Democrats.

Their most recent survey showed Bush with an approval rating of 62%, including the approval of 29% of Democrats and leading Dean 59% to 37%.

An approval rating of 62% while receiving 59% of the vote would suggest that most people who approve of him would vote for him, so this must include many of the 29% approvers who consider themselves Democrats.  Who are these people????

Others I would consider swing voters are:
1.the roughly 10% of the population that consider themselves independent
2.Conservative Republicans who are unhappy with the large budget deficits and libertarian Republicans.

Any analysis of who has the best chance to win, and how do the Democrats win in 2004 should focus on winning over these 3 groups of voters.