There is always a balance of self interest and common interest in politics and self-interest is the primary factor for individual politicians.
However, there is a taboo in democracies for politicians to be honest about their motives.
Most people other than those blinded by partisanship, believe that self-interest is the dominant factor but the fiction of it being the reverse has to be maintained.
There is nothing wrong with self-interest being the primary factor. It's the same with doctors who serve the community and in every profession, there are a minority of individuals where the mix of self interest and common interest is lopsided.
Honesty about motivation would be a better context for example to review special pay arrangements that have been made for TDs (members of the Dáil, the Irish parliament), some of the best paid politicians in the world, relative to responsibility and legislative workload.
If Mary Harney who resigned today as leader of the Progressive Democrats, decides to retire next year from the Dáil, she will have a pension for life at 54, starting at €100,000 annually! A TD, without ministerial service, gets a pension of almost €50,000 annually after just 20 years of service while 900,000 Irish workers have no occupational pensions.
Stephen Collins in The Irish Times reported last July that politicians received their fourth pay rise in a year at the beginning of June, bringing the basic salary of a TD to €96,560 before special allowances and expenses are taken into account.
For the Taoiseach and his Ministers, it was the sixth pay rise over the past 12 months. Mr Ahern's salary is now €258,730 a year, including his TD's salary, while the Tánaiste earns €222,256 and other members of the Cabinet get €204,020.
Each minister has got 2 benchmarking awards, even though everyone knows that the system has been an absolute scam.
Find more details on the system that has given legislators a 120% rise in 10 years, while their constituents on the average industrial wage have got 60% (when pensions are taken account of, the disparity is even greater) here - scroll down to lower end of page.