Hence the only other sensical hypothesis — namely, Trump’s self-interest — which even conservatives need to admit has become much more plausible following Michael Cohen’s guilty plea this week. The president’s former fixer now admits that he lied to Congress over the timing and extent of his efforts to make contacts and win contracts in Moscow on behalf of the Trump Organization, which lasted until at least June 2016, after Trump had essentially clinched the Republican nomination for president. By then questions about his Russia ties were fast becoming a political liability.

Now the president and his apologists are mounting an astonishing defense — accusing Cohen of being a liar while insisting there was nothing wrong with the very business dealings Trump previously lied about. If Cohen is lying, why does the president now freely admit to the truth of Cohen’s claims? If there was nothing wrong with the dealings, why did candidate Trump repeatedly deny them?

The contradiction here would be too inane to mention if it weren’t also insidious. Falsus in uno, falsus in omnibus. If the president tacitly admits to lying about his business interests in Russia, it’s unsafe to assume anything else he says about those ties is true.