The social basis of politics

It's local election day. Taking my daughter to school in leafy North Oxford I usually park in one of the area's swankier roads. A quick search on house prices suggests that when they (rarely) change hands it's for £3,000,000 and upwards. To my surprise I noticed today that the only political posters (adorning 3 very large houses, one with 2 Mercedes in the driveway)  were...for the Labour Party. Should that raise an eyebrow? Or have I just  forgotten that being wealthy doesn't necessarily imply that you want to keep it all for yourself?