Swing voters are more appropriately known as the 'idiot voters' because they have no set of philosophical principles. By the age of fourteen, you're either a Conservative or a Liberal if you have an IQ above a toaster.
When we were at peace, Democrats wanted to raise taxes. Now there's a war, so Democrats want to raise taxes. When there was a surplus, Democrats wanted to raise taxes. Now that there is a mild recession, Democrats want to raise taxes.