can a bank pay the NSF for a political account?

I'm not sure where you are located, but check with your state's election commission.

Regardless of your state's direction, I would never pay a political account into the negative. I might call and tell them if they bring $x in by 10am to cover the OD I'll pay them, but I wouldn't just let it ride.

in my state (La) a political account must remain in good standing...ethics charges if otherwise handled (not that ethics charges are done in a timely manner, may take a couple of years to get around to it).

any by political i mean the account held by someone running for political office, not a PAC.