> While I agree, surely the assumption that the Democrats will be more fiscally responsible isn't true either?

See the sibling thread parallel to yours, https://news.ycombinator.com/item?id=49329791

Democrats have a track record that speaks to them being more fiscally responsible than GOP, in spite of the rhetorical narrative.

You can't assume anything about the next crew. Past performance is no guarantee of future results. But if you're predicting fiscal responsibility, past performance favours the Democrats.

Past performance favors the democrats as president with republicans in congress. (there isn't much data with either party in charge of both branches)