The government has become so bloated that tariffs and excise taxes can no longer support it.
When we were founded as a country, we were supposed to have a very limited federal government. Hence the name United STATES of America. The states were meant to govern the people with a VERY limited federal government that would handle things the states could not. Things like border control, maintaining a small military, and handling foreign relations. Everything else, the states took care of.
However, in 1912 we elected a semi-socialist President named Woodrow Wilison who felt a larger centralized government would be better. He ruined the country forever by expanding the federal government beyond what was stated in our constitution and initiated a federal income tax to pay for it. Unfortunately, before our Supreme Court could knock down his policies, WWI happened.