Actually, in a way, I have to agree. The concept of Quid Pro Quo is essential to the political process.
Consider the Golden Rule. Even though you are also told to be kind to others without thought of repayment of your kindness, if you know that others follow the Golden Rule, then you can expect your kindnesses will be repaid.
You just can't be explicit about it.
This evening I could have said to my wife, "If I do the dishes, would you walk the dog?" proposing an exchange.
Instead, let's say I do the dishes. Later, when she says, "The dog needs a walk", and I say, "Could you walk the dog? After all, I did the dishes." is that a different situation from the first one?
And this is where Blago is something of a dolt.
Of course one gains influence by doing favors to others in politics.
We even consider "loyalty" to be a virtue - and a component of that is to remember favors done and to repay them with further favors. We start this with our kids.... "Well of course you should invite Sally to your birthday party. After all, she invited you to hers last month." We finely calibrate our "gift giving" rituals in accordance with gifts received or anticipated from others. It is an embarrassment to receive a gift from someone to whom you do not have a reciprocal gift. To avoid it, we organize rituals like 'secret Santa', 'gag gifts', or 'no gift' policies in workplaces.
Blago has confused virtue with commerce. And its that debasement of virtue (or some might say explicit acknowledgment of the exchange) that we find offensive.