[A] federal excise tax does not cease to be valid merely because it discourages or deters the activities taxed. Nor is the tax invalid because the revenue obtained is negligible. . . . [T]he instant tax has a regulatory effect. But regardless of its regulatory effect, the wagering tax produces revenue. As such it surpasses both the narcotics and firearms taxes which we have found valid.
It is axiomatic that the power of Congress to tax is extensive and sometimes falls with crushing effect on businesses deemed unessential or inimical to the public welfare . . . . The remedy for excessive taxation is in the hands of Congress, not the courts.