Since this is a recurring issue, I figure I should get my thoughts on the record. There are a lot of complaints about Congressional salaries, and it's a very easy issue to demagogue. But here's the thing,
the poor quality of the current Congress is partially the result of salaries that are too low in relation to the authority and responsibility of the position, and the associated costs of being in the public eye.
Congress sets policy for and has oversight of the entire Federal government. Individual Senators and Congressmen represent hundreds of thousands, if not millions, of people and serve as intermediaries between their constituents and government agencies. Attaining the office takes a degree of ability as well, including through the development of supporters and donors.
But the skills for attaining the office are different from the skills in being an effective legislator and leader. It's easier to grandstand, give speeches and attack disfavored groups through the law than it is to maintain control of the legislative process and conduct considered discussion of the law and the direction to take it.
Since there are two required skillsets, both of which require high levels of skill in order to be effective, under normal market conditions such a position would demand an extremely high salary in order to attract the most qualified people. But the political conditions instead keep the salary comparatively low.
These conditions only attract people who are interested in the non-economic rewards of holding office; the power, the connections, the platform as well as the incentives of corruption; bribes, corrupt dealings, and extortion, but only to those willing to go down that path.
This results in office-seekers who are motivated by selfish interest in power, rather than selfish interest in profit. The difference is simple - those interesting in profit will seek greater profit. Those interested in power will seek greater power, leading to ever-more expansive law and control, instead of more expensive offices.
But which, truly, is more costly? An expensive leader interested in his personal wealth, or a leader interested in controlling those under their authority?