"So you think that pure-bloods actually do have more power?" Hermione asked.
"Eh, not likely. In my experience, pure-bloods actually have the least power, overall. Just look at Ron or Draco. I could easily make a point of half-bloods having the most, though," Harry replied.
"Oh?" Hermione questioned, her eyebrows rising in surprise.
"Well, put it this way: over the last, say, fifty years, which European witch or wizard has been the most powerful?"
"That's easy," Hermione said. "Professor Dumbledore, of course."
"Easy," Harry said. "But wrong. Dum... all right, all right, Professor Dumbledore is number two. Voldemort - Tom Riddle - is actually a third or even half-again more powerful than the Headmaster is. And that doesn't include any power-enhancing rituals he might have done. Just the raw power he was born with."
"But... the Headmaster's the only person he's afraid of?"
"Skill makes a difference, Hermione," Harry said. "Professor Dumbledore has decades on Tom, even more because he's spent the last one essentially floating about in spirit form." He shrugged. "To continue, leaving off the Headmaster, who is the most powerful teacher at Hogwarts?"
Hermione opened her mouth to answer the same way as she had before, with assurance that she was right. But the previous answer had thrown her, so her tone was much more questioning when she responded, "Professor McGonagall?"
Harry grinned, but shook his head, "Your loyalty to her does you well, but Professor McGonagall is in her seventies, and her raw power has already started declining, as I mentioned before. The person I'm looking for is just off his or her final power spike."
Hermione frowned thoughtfully, then wrinkled her nose, "You mean Professor Snape."
"Aye," Harry replied. "All right, last question. Who, arguably, is the most powerful *student* at Hogwarts?"
"You," Hermione said, immediately. "There's noone else at the school who could chase off more than a hundred Dementors at once."
"That's not quite true," Harry replied. "But you'd never believe it if I told you who else could do it. Either way, that's pretty much correct." Harry wasn't blushing at all. It was like they were discussing the news.
"But that doesn't prove anything," Hermione said. "I mean, I know you're a half-blood, and so is V-Voldemort, but Professors Dumbledore and Snape..."
"... are half-bloods as well," Harry interrupted.