What did Donald Trump do today?

He gave exactly one sentence of reaction to the revelation that his son Donald Jr. had knowingly taken a meeting with a Russian government agent seeking to influence the election.

Told that the New York Times was about to report on the e-mails that formed the basis of their recent reporting about his efforts to obtain campaign help from an agent of the Russian government, Donald Jr. tweeted them himself. They show that, contrary to over a year of unequivocal denials on Donald Jr.'s part, he deliberately sought out the Kremlin's assistance to help his father get elected. Also present at the meeting were Jared Kushner and Paul Manafort, both of whom had already been caught concealing ties that lead back to Russia.

Deputy press secretary Sarah Huckabee Sanders gave Trump's only comment of the day: "My son is a high quality person and I applaud his transparency." Sanders referred all subsequent questions about the matter to Donald Jr.'s criminal defense lawyer.

However, Trump has more to fear than the damage to his son's reputation--or even Trump Jr.'s likely criminal exposure. Like his son, Trump has repeatedly sworn that he had no knowledge of any Russian effort to help his campaign, and that he never conspired with Russia to get elected. Those claims now hinge on the idea that neither Trump's own son, nor his son-in-law (Jared Kushner), nor his campaign manager (Paul Manafort), nor the Trump associate who arranged the meeting (Rob Goldstone), nor the Russian billionaire and friend of Trump who arranged things on the Russian side (Aras Agalarov) ever mentioned any of the details given in the e-mails to Trump.

Why is this bad?

• If there were an innocent explanation, now would have been when a president who hadn't conspired with a hostile foreign power to get elected would have offered it.