Last week Donald Trump's impeachment trial went just about as well as the White House could have hoped.
Yes, there were emotive pleas from the Democratic prosecutors, excoriating the US President's "dangerous" behaviour as they lobbied hard for his removal.
But the facts were not new, having almost entirely been revealed last year, and there were few signs Republican senators, who hold the body's majority and thus the power, were swayed.
That changed yesterday. Suddenly here was a new claim, made by someone allegedly with first-hand knowledge, about an issue at the heart of the impeachment case.
John Bolton's reported account is so eye-catching as it speaks to the central question - whether Trump used nearly half a billion dollars of taxpayer money for his own benefit.