The painful joke in Washington, D.C., is that while there are two political parties in America, there are actually three political parties in the U.S. Congress: Republicans, Democrats, and Appropriators.
This provides no challenge to the modern Democratic Party. Democratic appropriators are professional lifelong spenders of other people's money. Ordinary Democratic congressmen are too. They are simply jealous of the appropriators' proximity to the cookie jar.
For Republicans, appropriators who wear the Republican jersey became a fifth column -- congressmen who saw themselves as "spenders" in a party whose platform, leaders, and press releases tried to brand the party as the one dedicated to reducing government spending. When Republicans controlled Congress, GOP appropriators also found that they could raise campaign funds in return for sticking earmarks into legislation. This meant that the 36 Republican appropriators in the House and the 18 Republican appropriators in the Senate found they could afford to spend less time appealing to conservatives back in their districts. Over time, appropriators tended to become spenders first, Republicans second, and conservatives less and less. Worse, the trading of earmarked appropriations for campaign contributions, a practice known as "pay to play," is considered an art by Chicago Democrats but corruption by suburban and rural Republican district voters. And eventually such pay to play does in some cases become undeniable corruption very much damaging to the Republican brand, as in the tragic case of Rep. Duke Cunningham (R-CA), who resigned in 2005 after admitting to taking millions in bribes.
Beginning during the height of Republican control of the House -- before most Republicans were willing to see the problem -- there was an on-again, off-again campaign to term limit membership on the Appropriations Committee to six years, on the theory that no Republican would then see himself as a permanent member of the spending class. The Budget Committee, created in the 1974 Budget Act, limited its members to six years, not just for the chairman, but for membership on the committee itself. Perhaps the power held by appropriators and the resulting corruption could be limited through term limits.
A different approach now gaining support builds on an example from recent history of a successful structural reform that actually saved taxpayers money and eliminated government programs.