[Chesterbelloc]

Why does she continue to get access to these events when she is a known disruptor?

Because Democrat members of congress, eager to show that they are still not the grown-up party, continue to give them passes.

[Sam Hill]

And as others have suggested earlier, so that Maxine Waters can pretend that this was just a spontaneous outburst from a typical American fed up with the war:

"After witnessing Benjamin's disruption, Maxine Waters, member of Congress and chair of the Out of Iraq Caucus, stated, "We are going to witness more and more public outrage as the violence in Iraq escalates in this ongoing occupation.""