If your organization is so all fired important and popular, why do you need a government handout? If your members won't support you, maybe the problem's your organization. Are you based on the same principles as when you first started? Examine your owner motives. Reevaluate your effectiveness.
Justification for tax exempt organiztions
Tax exempt organizations collect relatively small donations from individuals (taxpayers who have paid tax on those donations). They then use those donations to “speak” on behalf of those individuals by purchasing TV, radio, print exposure, or other means of getting their message out. This allows the “little” and sometimes the “big” guy to engage in free speech that otherwise would be unavailable to him. Taxing the organization would result in double taxation which really wealthy individuals avoid by directly purchasing the media exposure. It gives the little guy an equal voice ($ for $) since his donation is not taxed twice.
Another way to look at it. A rich guy earns 250,000 and pays tax of 100,000 then buys an add for “xyz” from a TV station. 1500 poor folks earn 125 each pay tax of 25 and donate 100 each to an organization that is not tax exempt. They have income of 150,000. They can not purchase an add against “xyz” because the organization must pay tax on that income. Even though the organization represents 1500 individuals it can not compete with the one guy who can afford to purchase the add himself. That is the basic justification for tax exempt organizations. Tax payers money is NOT being spent on them.