Personally I'd be far more interested to learn that someone running for office refuses to use a credit card to buy groceries because they fear having that information collected and used against them... than that they once spent $500 in a single month on Twinkies.
If someone wants to use your spending history against you they don't actually need your credit card bills these days, they can just make something up. Look at the insanity that people managed to create out of John Podesta's office pizza orders.