Whatever you pay in taxes would one dollar more change your behavior? Of course not. But what about one dollar more? and one dollar more? As at the grocery checkout counter at some point you would or would not buy the candy bar based on a single penny. It might not be rational; you might not be able to say why "that is too much," but at some point you will think it is too much.
The principle matters because there are people who think this is not true. For example here is a guy who thinks an 80% marginal tax rate wouldn't dampen behavior (to be fair he also favors the "screw em" school of thought). It takes great moral certitude to think that gum at the checkout isle is resistible at a penny more but taxpayers are indifferent to "one dollar more..."
One dollar more per household is an extra $100 million dollars a year. One dollar more is $200 million, and who could object to that? Count high enough at we get to Bush's last budget of "one dollar more" which comes out to $30,000 per year per household ($5k/yr of debt). Obama's recession fixing budget is about $47k per year per household ($22k/yr of debt) in his first year and - he promises if you reelect him and rosy growth estimates come true - will "shrink" to just $50k per household year (and back to the Bush $5k/yr of debt).
I can feel the hope and change already.