Note that some cappos (e.g., Soros) don't fight progressive taxes and the welfare state.
It's too simple to see politics simply in terms of class vs. class, even if we could ignore the systems of patriarchy and ethnic dominance. Within each class, there's a difference between the long-term class interest and individual interest (usually short-term). Individual capitalists typically want lower taxes _on them_; whether or not it's a progressive tax is only an academic issue to them. Individual capitalists typically want the government to do only those things that benefit _them_ in the most direct way; whether that involves a "welfare state" is again only an academic issue to them.
Arguably, progressive taxes and the welfare state stabilize capitalism and are really good for individual capitalists in the long run. But this is a big issue of debate for the class. The only rock-bottom class interest that they can always agree on is the direct preservation of their class system using force. The only way that they can tell what their "true" class interest is after the fact. Marxists have an idea of what the capitalists' class interest is, but they'd never listen to us.
Are the capitalists suffering from delusions? Not really. It's more of a conflict between the "sure thing" of what seems to be individual interest and the unknown of class interest.
This means that we often see a fluctuation between capitalist policies that serve the short-term interests of the most powerful sections of the capitalist class (e.g., the Bush admin's policies) and those that clean up the mess and try to rationalize capitalism to promote its long-term health (e.g., the Soros program).
Historically, the only times when the latter types of policy persist and prosper are those when there's a large non-capitalist social movement (militant unions, the civil rights movement, the anti-Vietnam-war movement, etc.) and/or a Great Depression-type disaster pushing and/or scaring the capitalists to look for long-term solutions rather than to quick benefits for powerful cronies. -- Jim Devine / Bust Big Brother Bush! "There is no abstract [model in economics]. You must always start with something. Afterward you can remove all traces of reality." -- Pablo Picasso [paraphrased].