Some things to consider...
1) The real national deficit for Fiscal Year 2016 was $1.42 Trillion - no, Obama didn't cut the real deficit in half.
National debt up $1.42 trillion in FY 2016 | Washington Examiner
2) The national deficit is set to start rising under current law.
https://www.cbo.gov/publication/45010
3) Trump's plan would add Trillions to the debt.
Donald Trump's tax plan would add trillions to the debt - CSMonitor.com
4) We are at historic low interest rates and our bonds are also at relatively historic short duration -- meaning if interest rates rise our debt will accelerate faster as these low interest rates aren't locked in for the long-term.
Other countries are offering long-term bonds. Ireland, Mexico, and Belgium are offering 100 year bonds. Austria is offering 70 year bonds. Italy, France, Spain, and the UK offer 50 year bonds. Japan is offering 40 year bonds.
Many pension funds would buy these.
If we were able to sell 50 year bonds at the same rate the UK has, we could save $1,000,000,000,000.00 in interest payments over the course of 10 years - if projected interest rate increases happen.
Why Not 100-Year Treasury Bonds? | RealClearMarkets