HPVerse question: What if Dumbledore didn't say No?

[Fjolnir]

I was just thinking about this a little while ago but it seems like the big turning point in the entire series takes place before Harry's parent's death, possibly even before The Prediction (timeline is strange here), and that point is a young Voldemort, coming back to Hogwarts in an effort to become the defense against the dark arts professor. Dumbledore turns him down, but what if Tom Riddle became a professor? Would he still have been the terrible destroyer of the wizarding world and the greatest dark magician of the modern age had his other ambition been met? Could he have subsisted just by being the creepy evil magician on staff? I am genuinely curious what you all think about this.

[Mauve Shirt]

Well, he would have attempted to steal a bunch of items to use as horcruxes. Maybe he would have succeeded. He already had 4 or so at that point, IIRC, so he was getting pretty evil. Probably a little more noseless.
I wouldn't have trusted him with a Defense Against The Dark Arts curriculum. He'd have turned it into The Dark Arts Are Wicked Cool like those Death Eaters in the 7th book.

[Anarion]

With the resources available to him, Voldemort might have defeated Dumbledore and taken over the school and most of the wizarding world. Or, he might have become arrogant, pushed the issue, and been defeated by Dumbledore decisively. It was probably a close enough call that Dumbledore wasn't willing to take the risk. Bringing things to a decisive battle that you're not confident of winning usually isn't a great plan for either side.

[Traab]

Its possible voldemort wasnt even interested in the position really, that he wanted a chance to get into hogwarts and hide his horocrux there. It seems highly unlikely he would have brought one with him otherwise.

[Dr.Epic]

I honestly don't see how it would make a difference. Remember all those teachers at Hogwarts that turned out to be evil? I doubt the need to grade papers would stop him.

[Agincourt]

Voldemort probably would have inflicted more damage long-term, but a lot less in the short-term. Hogwarts was the only place that Tom Riddle ever felt at home. I think his desire to be a teacher there was sincere, but not benign. He probably would have stayed there a long time and been a successful teacher—probably too successful—and taught many students too much about the dark arts.

As a power-hungry psychopath, he would have used students for his own ends. At the end of Deathly Hallows we get the impression that Harry helps forge a new wizarding order, with an emphasis on ability instead of heritage. That would not have come to pass if Tom Riddle were a teacher. Not only would everything not have come to a head that allowed Harry et al. to build anew, Riddle would have been actively undermining Dumbledore's desires for an egalitarian society.

[Gnoman]

He would have had every student that went through Hogwarts under his thumb for 5-7 years. Besides the opportunity to mold students to his views, he would have been able to easily vet the students, keeping his likely enemies underprepared, and preparing those that would serve him.

Basically, Dumbldore would have given him a high-capacity recruitment center for Death Eaters. That would not have gone well.

[felinoel]

I honestly don't see how it would make a difference. Remember all those teachers at Hogwarts that turned out to be evil? I doubt the need to grade papers would stop him.xD
This is a very good point here.