[edit] Thanks, that helps, but I still don't understand what you think is being correctly or incorrectly incentivized here.
When a majority of a countries people are not paying for the country or (worse) profiting off the government, then they have no incentive to keep government spending under control. This leads to the increase of tax money coming from fewer and fewer citizens until the whole thing collapses. Paying for something means that you pay more attention and be more critical of failures.
Of course people have little incentive to find out which policies will bring actual good results as opposed to those which superficially seem nice. Luckily politicians who hope to be reelected can't do anything that turns out to be too stupid in practice... some fraction of the time. And so we sort of muddle our way through things.
So while your post makes a lot of sense on an individual basis, it seems that self-interested groups are almost certainly a factor in the way people vote. It would be pretty easy to miss this looking at things like income or age; I'd be more interested in seeing studies based on union affiliation or some other sentient grouping (as opposed to a non-sentient group like "people over 60").
1) The history of the 2000 election actually makes a serious point about polling and the failure of a news organization (Fox) to realized polls hadn't actually closed in the panhandle of Florida (Central Time). That area of Florida is heavily Republican and lower voter turn out because of the pre-announced winner (Gore). A few more Democrats voting or a non-preannouncement could have prevented one of the stupidest episodes in US voting history. Vote like you've heard nothing.
If that was the case, then you would expect to see most of the rich as republicans, but in actuality a lot are democrats. Taxes are not the most important issue for a lot of people in the upper class.
Lets forget the social issues which can be drivers of that, and focus strictly on the numbers.
A rational person wants to maximize the amount of money they have in their pocket at the end of the day. If government policy had no influence on the economy then obviously the best way to do this is through lower taxes.
But what if government policy does have an influence on the economy? I would rather pay 35% taxes on $100,000 than 30% taxes on $80,000.
This effect gets magnified at the top, especially when bonuses are in play.
Believe it or not, history has shown the economy to be better under democrats than republicans in the post-war period, and this will only become further exacerbated because this data doesn't include what has happened in the last 2 years.
It's important to note this doesn't take into account national, state, and local taxes that everyone pays regardless of income including sales, gas, and property taxes, tariffs, filing fees, tolls, etc. The whole "who pays federal income tax" argument is somewhat of a red herring.