Here is an extreme libertarian type (wrongly identified, I think, as a Tea Party type by Gawker, etc.), Greg Collett, father of 10, from Utah, going all Ayn Rand on social programs he makes use of.  Which is to say: “I’m against Medicaid, but I use it for financial reasons” (or something, because he doesn’t really say why). He writes:
The vast majority of the comments directed towards me try to paint me as a hypocrite for being a limited government advocate and having my kids on Medicaid. My political beliefs are certainly not popular, and in this case, there are many people in the liberty movement who want to take me to task. Again, we are dealing with a situation where people have been socialized into believing a lie.
Let me set the record straight. Yes, I participate in government programs of which I adamantly oppose. Many of them, actually. Am I a hypocrite for participating in programs that I oppose? If it was that simple, and if participation demonstrated support, then of course. But, my reason for participation in government programs often is not directly related to that issue in and of itself, and it certainly does not demonstrate support. For instance, I participate in government programs in order to stay out of the courts, or jail, so that I can take care of my family; other things I do to avoid fines or for other financial reasons; and some are simply because it is the only practical choice. With each situation, I have to evaluate the consequences of participating or not participating.
Collett is a kind of anti-government purist (all government taking is theft, essentially). He doesn’t personally carry health insurance, but he uses government programs (Medicaid but not public schools–you really have to read the manifesto) to cover his children. Children are expensive, sickness is expensive and can be financially devastating. His choice of Medicaid to cover his children (as well as his choice of becoming a foster parent to eight children) demonstrates that perhaps his insistence that government leave this role is not actually feasible. It’s nice, in other words, to have ideals, but seriously, they have to be practical.
And this is a critical point about non-fallacious tu quoques. They do not demonstrate that your beliefs are false. They demonstrate that your beliefs may be too hard to put into practice if not even you, ardent exponent of milking your own cows, cannot do it.
*Here’s the rest of the Emerson passage (from “Self Reliance”):
 A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines. With consistency a great soul has simply nothing to do. He may as well concern himself with his shadow on the wall. Speak what you think now in hard words, and to-morrow speak what to-morrow thinks in hard words again, though it contradict every thing you said to-day. — ‘Ah, so you shall be sure to be misunderstood.’ — Is it so bad, then, to be misunderstood? Pythagoras was misunderstood, and Socrates, and Jesus, and Luther, and Copernicus, and Galileo, and Newton, and every pure and wise spirit that ever took flesh. To be great is to be misunderstood.