What factors have contributed to the large deficit and increasing National Debt in our government? Is there a solution in sight?

Believe it or not it has very little to do with what congress decides to spend on an annual basis, through discretionary appropriations, and a lot more to do with future obligations congress has authorized through mandatory spending on social security, Medicare, Medicaid, Veterans Benefits etc. Mandatory spending takes up the lion’s share of the federal budget constituting almost 2/3 of all congressional spending. Social Security accounts for about 1/3 of mandatory spending and slightly more than 1/5 of all congressional spending while Medicare and Medicaid combined account for 2/5 of mandatory spending and 1/4 of all congressional spending. Thus, the bulk of mandatory federal outlays are spent within the human resources budget function. It is also the fastest growing portion of the budget doubling from 2 trillion just a decade ago to about 4 trillion in FY2023, an increase which exceeds the FY2023 deficit. Discretionary spending, by contrast, only increased by 33% and $400 billion between FY2013 and FY2023. With interest on the National Debt taking up about 11% of the federal budget ($678 billion) discretionary spending only makes up a little more than 1/4 of the federal budget.

The course for perpetual deficits and national debt growth has already been set by prior generations. Most of the rapid growth in mandatory spending is due to an aging population that relies on Social Security and Medicare. The number of Americans over 65 years of age increased by 15.5 million, the largest ever numeric gain over a decade, from a little over 40 million Americans to almost 56 million Americans by the 2020 Census and is growing at a much faster rate than the total population itself which increased by about 20 million over the same period. Thus, social security spending has increased from about $800 billion paid out in 2013 to $1.4 trillion paid out in 2023. Much of it is also due to price hikes for medical care and prescription drugs, the bulk of which goes to senior citizens. Thus, Medicare spending has increased from $492 billion in 2013 to $846 billion in 2023 and Medicaid spending has more than doubled from $265 billion a decade ago to $536 billion FY2023. Veteran's benefits have more than tripled from $80 billion to $300 billion in the same time period. Total healthcare spending in the U.S. has increased by over 50% from less than $3 trillion in 2013 to $4.5 trillion, about 20% of GDP, in 2023. These costs will only continue to rise with an aging population and increasing rates of chronic disease and cancer. Of course, cutting these mandatory spending programs is a third rail that would inevitably result in political suicide thus there is no feasible way to cut the deficit or national debt.

I originally answered this on Quora