A soccer mom literally means a mom that picks up her kid(s) after soccer practice. However, the term has come to mean the notion of a white married female in the age range of 30-49 with 1 or more children in an American suburb. She is typically thought to be concerned only about her own welfare and that of her children often at the peril of others. This selfish attitude is typified by their bad driving habits, and driving unnecessarily large vehicles like SUVs, which shows their carelessness about concepts like protecting the environment. The are typically but not always Republican, which is another example of their lack of care for the rest of humanity. They prefer Republican over Democratic usually because they believe the Republican party spares them from having to pitch in to help the needy in society, that the Republican party "protects" them better against terrorists and foreign threats, and that the Republican party is more "godly" and against abortion and homosexuals. The last point was actually exploited greatly by George Bush in his last two elections as his campaign appealed to Soccer Moms sense of vulnerability numerous times. Indeed, if it wasn't for the vote of Soccer Moms, Bush may never have been re-elected.
They may also be blindly right-wing Christian. They blindly believe in a religion handed to them by their parents. They have never questioned it, or deeply thought about it. They simply know they are Catholic, Protestant, or Evangelical, and so will be their kids. They are afraid of people of color, other religions, and any thing other than suburban, white, republican, heterosexual, middle or upper-class, christian, and "American" (which is a bigot's definition of American).
Soccer Moms, are usually the next phase of the life of a "gold-digger" after she lands a financially well-off male to live off of.
The millions of Soccer Moms that voted to elect Bush in 2000 and 2004 because they wanted "God" in American life and were afraid of terrorists hurting their kids.