What did Donald Trump do today?

He signed a tax bill just in time to have its basic assumptions contradicted by his own government.

Trump--openly worried that the spotlight was already fading on the first significant piece of legislature passed during his presidency--abruptly decided to sign his tax bill today at a hastily arranged Oval Office ceremony. In remarks made during the event, Trump insisted that the bill was "becoming very popular." In fact, in a CNN poll taken just before its passage, voters disapproved of the bill by a margin of 35-59%. This makes Trump's tax bill, which massively reduces taxes on the wealthy but includes at least token cuts for low- and middle-income filers, less popular than several tax hikes.

Several hours after the signing ceremony, the Joint Committee on Taxation (JCT) announced in its final report that the bill would not come anywhere near to stimulating the economy enough to make up for the $1.5 trillion hole it will put in the federal budget. Quite a few independent analyses had already concluded this, but the JCT is a Republican-led congressional committee charged with analyzing the financial impact of tax legislation for the government.

The Trump administration's official position was that the tax cuts would pay for themselves, although it announced this claim in a one-page document based on extremely optimistic assumptions that one economist called "a joke."

Why should I care about this?

• Good legislation doesn't need to be lied about.

• Whether a president gets "credit" from media he claims to hate should be less important to him than whether he's actually doing his job.