I think most government workers including elected officials in both parties will be biased towards spending and granting themselves more power over time. I think if each party actively damages the other party's cherished institutions and programs (eg by creating policies undermining the defense industrial base, or undermining SNAP) it will require excess spending just to stand still. Each party is stuck rebuilding stuff every 4 years and nothing gets done for either party's agenda, at astronomical expense. Tragic, and obviously unsustainable. In a perfect world, liberals push spending on useful well run programs and conservatives resist foolish spending on fads and over zealous interventions and policy with little impact. We need that balance. We do not have it. As such, those that want to burn it all down will win, unless the left change their ways. (Moderates on the right are and forever will be outgunned by the more intelligent, typically wealthier Milton Friedman types.)