IRS - Not-so-shocking news about IRS - In Washington, it was discovered that the Internal Revenue Service had access to some taxpayers' political party affiliations. But this shouldn't have come as a shock since this information is available to anyone. This lack of privacy has caused some voters in Washington to fight any attempt to require party registration.
All government and all agencies are run by people, and it is the innate nature of people to form opinions and even discrimatory penchants. This holds especially true if people are in a group that has an opposition, such as political parties. If the IRS was dominantly controlled by a certain political group or influenced by certain policies, it might be inclined to give favor to those who belong to their group. Also, this could be seen as an infringement upon citizen's privacy.