Additionally while you will take a temporary hit to income, you will be working on projects that have real impact on the lives of every american in the country. You will be empowered to make changes and do what is right at the highest level of the government. You will be heartbroken at the amount of need, and the amount of pain that is caused by things you can fix. You will be exposed to all the failures of the government, and you will be right at the center of some of its greatest successes. At the end of your tour of duty you will be sad that there wasn't more you could do, but you will be forever grateful for the opportunity to have served and to have made the country better. You will probably leave not even looking for the most money at your next job, but just trying to figure out how you can continue to have purpose anywhere near the same level you just experienced.
If you are on the fence do it.