Ideology? Not at all. Waste. Waste. Waste.
I'm a strong proponent of making dead certain that each one of our military branches is the strongest of type in the world BUT the R&D process is so full of waste it is obscene. Lobbiests and backslapping politicians have spent decades creating processes that are less focused on introducing the best technology to the field than they are on enriching themselves. For a very good example of the excesses read the book
Boyd.
In regards to the flat tax, I firmly believe absolutely every single person living legally in the US should pay income tax or no one should. As I've described in the past, my view on a flat tax isn't really flat but I truly believe 1% on every single dollar up to $50-60K and 20%(ish) on every dollar of personal income over with no deductions beyond first home mortgage interest would solve many problems.
After you get that done let's talk about my version of comprehensive immigration reform.