His decision wasn't prompted by the counsel of his advisors, or some ingenious political revelation—he signed the bill into law to prove the losers and haters of American cable news wrong.

"I was going to wait for a formal signing some time in early January, but then I watched the news this morning and they were all saying, 'Will he keep his promise, will he sign it by Christmas?'" Trump said during the signing. "And I called downstairs and said, 'Get it ready, we have to sign it now.'"

Though the president sometimes denies it, Trump is obsessed with cable news, and TV has helped fuel his fits of rage. On Friday, it seemed to affect more than that.

The spending cuts that could be triggered by the bill could be waived by Congress, but that would require Democrats to cooperate with Republicans. Addressing it will likely be a priority for legislators as soon as they come back to DC after the holiday break.