Clinton was able to run a federal government spending less than 20% of GDP, since George Walker Bush federal spending has exploded to the 25 to 30% range. The reality is that 20% is plenty, and can solve all the problems government has the ability to solve.
Need to start by NOT
1) serving as the worlds policeman
2) building double the aircraft carrier tonnage of the rest of the world combined.
3) spending a trillion dollars on newest latest fighters not ready for service when we aren't at war
4) staging US troops and ships in the Middle East or Europe when both are immensely wealthy and able to defend themselves.
5) pouring $40B into a launch system design based on obsolete technologies and an overweight deep space capsule that needs a year to replace a single bad power unit.
6) subsidizing professional sports leagues paying millions a year per employee. etc, etc.
A good start would be requiring senators and congresspeople to recuse themselves from any legislation that specifically allocates funds for any projects in their states/districts. Get away from the thousand page earmarked pork funding bills and focus their responsibilities on legitimate national interests.