I've got children. There are things more important to me than smug self-congratulations.
To the contrary, I think it is you who hasn't read the quote you offered very closely. That quote wasn't about success, or some strategic plan for eventual victory by sticking to your principles. It was simply about feeling good about yourself because you insisted on 100% purity. When my kids are in a country with a 6-3 liberal majority on the Supreme Court, with electoral demographics permanently skewed because of liberal immigration policies, me self-congratulations won't be of any solace to them.
You have children? Then the best thing you can teach them is to be true to your principles. Even your political principles. Do not compromise your values. Hold fast to your fundamental truths.
I don't see voting for an imperfect candidate as a compromise of values, or a failure to hold to fundamental truths. You can vote for a less than perfect candidate on the basis that he is better than the alternative, and also be vocal about opposing anything he does, or attempts to do, that is inconsistent with your principles.
In essence, you are voting for that person, warts and all, because that's the nature of the two-party system. But you are still free to speak out and oppose him/her to the extent they push policies you do not support.
I also am in agreement with those who believe that internal party pressures and the need for the candidate to retain support will compel any Republican nominee to be more conservative than the Democratic alternative once elected.