David A. Graham reports at The Atlantic:
Trump campaign chairman Paul Manafort was already in the midst of a rough spot when The New York Times published a story Sunday night, detailing millions in cash payments to Manafort listed in a secret ledger in Ukraine.
By Friday, Manafort had resigned from the Trump campaign, two days after the Republican nominee effectively sidelined him by hiring a new campaign chief executive and a new campaign manager.
The story nicely enumerates the growing list of scandals surrounding Comrade Manafort.
Those revelations made Manafort politically toxic. (Rick Gates, a longstanding Manafort aide who was also implicated in the stories, has also reportedly resigned.) But Manafort’s demise may have been driven by Trump’s floundering standing in polls as much as by the bad press. Trump, after all, likes to win, and he hasn’t been doing much of that recently.