We have a republic (i.e. a representative government), but it is a Democratic Republic not a federal republic anymore. Without state government representation in the government there is no federation...we have a unitary system where the states more resemble provinces rather than states.....we have a Democratic Republic that claims to be federal but doesn't act like one in practice at all.
I should have used “Democratic Republic”. Certainly, it gives no check on the growth of the corruption in Washington. The original founders model was far better.