As told in the story line the rate of magical children born to muggles is increasing. Some say it is natures way of merging the muggle and wizarding worlds. However others fear it will lead to war between the two worlds and with the ever growing world of muggles they may not win..
It is the plan of Terran Onyx, a prodominate member of the wizengamot, the all muggle-born children should stripped of there powers and sent back to live in the muggle world. There are those who oppose him of course, the current minister of magic included. It is argued without muggle born witches and wizards the magical peoples could die out forever. Terran argues that at the rate muggle were finding out about there world it would not remain a secret for long, and that despite there magic's they may not stop a war that would break out... It was not about blood he argued, it was about the security of the wizarding world.
His proposal was dismissed as to harsh and radical to even concider, however it is doubtfull he will let the matter drop.
Secretly he gathers followers to find Muggle born children and rip the magic out of them with a spell he had developed....