"If your opponent is of choleric temperament, seek to irritate him." - Sun Tzu
I refuse to accept the view that mankind is so tragically bound to the starless midnight of racism and war that the bright daybreak of peace and brotherhood can never become a reality. - MLK
They also benefit more from FDIC insurance, and have much greater individual control of our politicial system through their financial contributions to politicians.
Additionally, wealthy people use the court system much more than poor people, both personally and through their businesses. Through their businesses and business ownership, they use the roads, import/export facilities and legal system.
So, no, wealthy people don't use less or the same of the governmental "commons" as everyone else.
In an economy where demand exceeds production capability, yes a lower capital gains tax migh (and I stress MIGHT) help, but in reality if a business deal is good, a tax impact of 3% is not going to dissuade anyone from investing. In our economy, demand is low.