I'm assuming everyone is familiar with the concept.

The government treasury is now such a "commons," since long ago we institutionalized the idea of dispensing loot from it to the public and supporters in return for perpetual political power.

Responsible politicians who try not to drain the Treasury are overrun by other politicians who take the first politician's share as well as their own. End result is the Treasury is still drained. Added result is that the politician who refuses to distribute loot is voted out by voters in favor of those who throw the candy out the limo windows.

The unemployed person who tries hard to get by without government handouts gains nothing but self-esteem, while those who exploit such benefits to the maximum rake it in with no discernable penalty. Same for businesses who try to make it without subsides struggling while businesses who get special privileges and crony contracts succeed.

We may have gotten a small reprieve with the last election, but I am cynical enough to believe that a lot of the Tea Party types who want to see spending and taxes cut aren't going to be a monolith of resolve when programs they benefit from are actually cut. This is one reason the government has an incentive to make as many Americans as possible dependent on government largesse.

Recommended reading: "Not Yours to Give."