If we cut the budget in half, a 50% reduction, I'd say we could eliminate the national debt ($7 trillion) in about seven years. Cut the budget by 25%, we'd elminate the national debt in 14 years. Even with a 10% reduction, it would take some 35 years to eliminate the national debt.
And there is the considereation for national defense.
The #1 Constitutional priority is national defense.
Hopefully none because our taxes would be only enough to cover the constitutionally allowed spending.