Muggles' Guide to Harry Potter/Magic/Half-blood

Overview
A half-blood is someone with magical powers, having only one pure-blood parent, the other being either Muggle or Muggle-born.

Extended Description
"Half-blood" status is only important to those wizards who give weight to the "blood purity" beliefs, the unproven and legally unsupported belief that being able to prove Wizarding ancestry somehow grants additional status to an individual or family. To those who accept this belief system, a Half-blood wizard is inferior to one who can prove ancestry from Wizarding families.

Analysis
Given the apparent group hysteria displayed by the proponents of the Blood Status theory, we perhaps should not be surprised that no distinction is drawn between the child of a Wizard and a Muggle, and the child of a Wizard and a Muggle-born.

Due to some process likely akin to hybrid vigor in genetics, quite often the most powerful wizards and witches spring from these intermarriages: classic examples would be Harry Potter, Tom Riddle, and Professor Snape. Equally, weaker wizards can come from pure-blood families; examples here would be Merope Gaunt and, at least initially, Neville Longbottom. However, there is quite a large faction of wizards, headed by Lord Voldemort, who believe that only pure-bloods should be educated in magic, and in fact that everyone other than the purebloods should be wiped off the face of the Earth.

We will note that the pure-blood wizards are by no means weak. While we are given the impression of a decrease in abilities in the older families, notably in the case of Neville Longbottom and Merope Gaunt, we also see that Neville shows significant abilities in Charms and Herbology in later books, and we believe that Merope's problems stem more from actual inbreeding, than from simply extended heritage. Similarly, we note the wizarding strength of Bellatrix Lestrange and Lucius Malfoy, both of whom claim pure-blood heritage. Clearly it is as inaccurate to generalize about the relative strength of pureblood versus "hybrid" wizards in either direction, no matter what impression the author means to give us.

It is often hard to determine where prejudices start. While it's tempting to think that a prejudice is based on a truth of some sort, often the truth, if there is any, is misplaced or totally unrelated. It is possible that the belief in pureblood superiority originally started with something as simple as "we've been around longer, so we must be better;" it may not have anything to do with actual magical abilities. But as this prejudice clearly existed at the time Hogwarts was founded, possibly a thousand years ago, its origins are so far in the past as to be totally lost.

Questions

 * 1) What parallels can be drawn between instances in Muggle World History such as the Civil Rights movement and the role of Half-Blood characters in Harry Potter?
 * 2) If you were a half-blood wizard how would you feel knowing that Voldemort was in power once more?
 * 3) How far can you say that the tensions between Voldemort and half-blood wizards is at the heart of the Wizarding Wars?