Early in the week, anxiety over a government shutdown appeared to ebb as the short-term Treasury Bill market began to 'normalize', but following the tax-reform 'win', President Trump is accusing Democrats of trying to force a government shutdown...

House Democrats want a SHUTDOWN for the holidays in order to distract from the very popular, just passed, Tax Cuts. House Republicans, don’t let this happen. Pass the C.R. TODAY and keep our Government OPEN! — Donald J. Trump (@realDonaldTrump) December 21, 2017

...And the Bill curve has shifted notably more inverted...

While there are obviously year-end liquidity impacts involved too, it appears market anxiety is building as perception grows that Dems may move to stunt the Republicans' momentum from their 'victory' on taxes.