Already handled
Congress passed the Brown Ammendment through both Houses on a bi-partisan basis.
Since a group of Langley engineers has already established that the impact hazard may best be dealt by man-tended facilities based on the Moon (an analysis confirmed by adoption by China's space leadership), the cuts to NASA will be limited.
NASA has more responsibilities than simply flying a few men to Mars, and the US space effort is far larger than the fantasies of a few.