I'm always suspicious of Schumer's motives, but he cares more for the survival of the Jews in Israel than he does for the short-term political objectives of the Obama administration.
I hope the authors are right about the long-term damage to the Democrats from the agreement...which pales in comparison to the long-term damage to Iran's enemies once it can deliver its nukes to targets.
Nonetheless, Schumer’s vote isn’t needed so it’s appropriately “Kabuki”.
There might be some worry for Schumer that opposing Obama will hurt him with “black” voters. Can’t see it myself but he, no doubt, keeps a close eye on that aspect.